diff --git a/converter.js b/converter.js
index a88d948..72d9da5 100644
--- a/converter.js
+++ b/converter.js
@@ -1,151 +1,215 @@
-excelParser = {
-  latexEscape: function(text) {
-    escapeRegExpr = function(str) {
-      return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
-    };
+!(function($) {
+  "use strict";
 
-    var specials = ['\\', '&', '%', '$', '#', '_', '{', '}', '~', '^'];
-    $.each(specials, function() {
-      var regexp = new RegExp(escapeRegExpr(this), 'g');
-      text = text.replace(regexp, '\\' + this, 'g');
-    });
+  // Global variable with information on current workbooks. Don't judge me.
+  var workbooks = {};
 
-    return text;
-  },
+  // Another global to store LaTeX output. Don't judge me...again...
+  var latexOutput = {};
 
-  parseStringTable: function(data) {
-    var doc = $(data);
-    var stringTags = doc.find('si');
-    var strings = $.map(stringTags, function(s,i) {
-      return $(s).find('t').text();
-    });
+  var excelParser = {
+    latexEscape: function(text) {
+      var escapeRegExpr = function(str) {
+        return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
+      };
 
-    return strings;
-  },
+      var specials = ['\\', '&', '%', '$', '#', '_', '{', '}', '~', '^'];
+      $.each(specials, function() {
+        var regexp = new RegExp(escapeRegExpr(this), 'g');
+        text = text.replace(regexp, '\\' + this, 'g');
+      });
 
-  toLatex: function(table) {
-    var max = 0;
-    for(var i=0; i < table.length; i++) {
-      if(table[i] && table[i].length > max) { max = table[i].length; }
-    }
+      return text;
+    },
 
-    var numCols = max;
-    var args = [];
-    for(var i=0; i < numCols; i++) {
-      args[i] = 'l';
-    }
-    args = ' | ' + args.join(' | ') + ' | ';
-    var latex = "\\begin{tabular}{" + args + "}\n\\hline\n";
-    for(var i=0; i < table.length; i++) {
-      var cols = table[i];
-      // TODO: replace "&" with "\&"
-      if(cols === undefined) { cols = []; }
-      if(cols.length < numCols) {
-        for(var x=cols.length; x < max; x++) {
-          cols[x] = '\\ ';
-        }
+    parseStringTable: function(data) {
+      var doc = $(data);
+      var stringTags = doc.find('si');
+      var strings = $.map(stringTags, function(s,i) {
+        return $(s).find('t').text();
+      });
+
+      return strings;
+    },
+
+    toLatex: function(table) {
+      var max = 0;
+      for(var i=0; i < table.length; i++) {
+        if(table[i] && table[i].length > max) { max = table[i].length; }
       }
 
-      latex += "\t" + cols.join(' & ');
-      latex += " \\\\ \\hline\n";
-    }
-
-    latex += "\\end{tabular}\n";
-    
-    $('#latex-output').val(latex);
-  },
-
-  processSheet: function(data, stringTable) {
-    // get jQuery object out of the data for accessing stuffs
-    var doc = $(data);
-
-    var table = [];
-
-    var rows = doc.find('sheetdata row');
-    $.each(rows, function(i,row) {
-      var rowNum = parseInt($(row).attr('r'));
-
-      // get columns
-      var cols = $(row).find('c');
-      var colVals = $.map(cols, function(col,j) {
-        var col = $(col);
-        var val = excelParser.latexEscape(col.find('v').text());
-        if(col.attr('t') == 's') {
-          return excelParser.latexEscape(stringTable[parseInt(val)]);
-        } else {
-          return val;
+      var numCols = max;
+      var args = [];
+      for(i=0; i < numCols; i++) {
+        args[i] = 'l';
+      }
+      args = ' | ' + args.join(' | ') + ' | ';
+      var latex = "\\begin{tabular}{" + args + "}\n\\hline\n";
+      for(i=0; i < table.length; i++) {
+        var cols = table[i];
+        // TODO: replace "&" with "\&"
+        if(cols === undefined) { cols = []; }
+        if(cols.length < numCols) {
+          for(var x=cols.length; x < max; x++) {
+            cols[x] = '\\ ';
+          }
         }
+
+        latex += "\t" + cols.join(' & ');
+        latex += " \\\\ \\hline\n";
+      }
+
+      latex += "\\end{tabular}\n";
+      
+      return latex;
+    },
+
+    processSheet: function(data, stringTable) {
+      // get jQuery object out of the data for accessing stuffs
+      var doc = $(data);
+
+      var table = [];
+
+      var rows = doc.find('sheetdata row');
+      $.each(rows, function(i,row) {
+        var rowNum = parseInt($(row).attr('r'), 10);
+
+        // get columns
+        var cols = $(row).find('c');
+        var colVals = $.map(cols, function(col,j) {
+          col = $(col);
+          var val = excelParser.latexEscape(col.find('v').text());
+          if(col.attr('t') == 's') {
+            return excelParser.latexEscape(stringTable[parseInt(val, 10)]);
+          } else {
+            return val;
+          }
+        });
+        table[rowNum-1] = colVals;
       });
-      table[rowNum-1] = colVals;
-    });
 
-    return table;
-  },
+      return table;
+    },
 
-  handleSheet: function(entries, stringTable) {
-    // filter out all files that aren't worksheets
-    var sheets = $.grep(entries, function(n,i) {
-      return (/^xl\/worksheets\/.*\.xml$/.test(n.filename)) && (!/^xl\/worksheets\/_rels/.test(n.filename));
-    });
+    handleSheets: function(entries, stringTable) {
+      // get the workbook.xml file, which contains the names of all workbooks
+      var workbookMeta = entries.filter(function(entry) {
+        return entry.filename === 'xl/workbook.xml';
+      })[0];
 
-    // for now, only process the first sheet
-    // TODO: give the user a choice of which sheet to process
-    var sheet = sheets[0];
-    sheet.getData(new zip.TextWriter(), function(text) {
-      var table = excelParser.processSheet(text, stringTable);
-      excelParser.toLatex(table);
-    });
-  },
+      // filter out all files that aren't worksheets
+      var sheets = $.grep(entries, function(n,i) {
+        var filter1 = /^xl\/worksheets\/.*\.xml$/;
+        var filter2 = /^xl\/worksheets\/_rels/;
+        return (filter1.test(n.filename)) && (!filter2.test(n.filename));
+      });
 
-  handleFile: function(event) {
-    // prevent default browser behavior
-    event.stopPropagation();
-    event.preventDefault();
-
-    // get file information
-    var files = event.dataTransfer.files;
-    if(!files.length) {
-      // no files were given somehow...
-      $('#latex-output').val('No files were given...try again?');
-      return false;
-    }
-
-    var blob = files[0];
-
-    // unzip and process files
-    zip.createReader(new zip.BlobReader(blob), function(reader) {
-      reader.getEntries(function(entries) {
-        if(!entries.length) { return false; }
-
-        // get the string table
-        var stFile = $.grep(entries, function(n,i) {
-          return /^xl\/sharedStrings\.xml$/.test(n.filename);
-        })[0];
-
-        stFile.getData(new zip.TextWriter(), function(text) {
-          var stringTable = excelParser.parseStringTable(text);
-          excelParser.handleSheet(entries, stringTable);
+      // read the workbook meta data to get the names and crap
+      workbookMeta.getData(new zip.TextWriter(), function(text) {
+        var doc = $(text);
+        
+        // extract the names of the workbooks and their IDs for use later on...
+        $.each(doc.find('sheets sheet'), function(i, tag) {
+          tag = $(tag);
+          var id = tag.attr('sheetId');
+          var name = tag.attr('name');
+          workbooks[id] = name;
         });
 
+        excelParser.updateSelect();
+
+        // iterate over all sheets and convert them to LaTeX
+        $.each(sheets, function(_, sheet) {
+          // the ID of the spreadsheet can only be found in the filename apparently :P
+          var id = sheet.filename.match(/(\d)\.xml/)[1];
+          
+          sheet.getData(new zip.TextWriter(), function(text) {
+            var table = excelParser.processSheet(text, stringTable);
+            var latex = excelParser.toLatex(table);
+            latexOutput[id] = latex;
+            
+            // I apologize for the hack :(
+            if(id === '1') {
+              $('#latex-output').val(latex);
+            }
+          });
+        });
       });
-    });
-  },
+    },
 
-  init: function() {
-    // hack because of jQuery shenanigans
-    jQuery.event.props.push('dataTransfer');
-
-    $('body').bind('dragover', function(event) {
+    handleFiles: function(event) {
+      // prevent default browser behavior
       event.stopPropagation();
       event.preventDefault();
-      event.dataTransfer.dropEffect = 'copy';
-    });
 
-    $('body').bind('drop', excelParser.handleFile);
-  }
-};
+      // get file information
+      var files = event.dataTransfer.files;
+      if(!files.length) {
+        // no files were given somehow...
+        $('#latex-output').val('No files were given...try again?');
+        return false;
+      }
 
-$(function() {
-  zip.workerScriptsPath = 'zip/';
-  excelParser.init();
-});
+      var blob = files[0];
+
+      // unzip and process files
+      zip.createReader(new zip.BlobReader(blob), function(reader) {
+        reader.getEntries(function(entries) {
+          if(!entries.length) { return false; }
+
+          // get the string table
+          var stFile = $.grep(entries, function(n,i) {
+            var regexp = /^xl\/sharedStrings\.xml$/;
+            return regexp.test(n.filename);
+          })[0];
+
+          stFile.getData(new zip.TextWriter(), function(text) {
+            var stringTable = excelParser.parseStringTable(text);
+            excelParser.handleSheets(entries, stringTable);
+          });
+
+          return undefined;
+        });
+      });
+
+      return undefined;
+    },
+
+    updateSelect: function() {
+      var select = $('#workbook');
+
+      // clear existing option tags
+      select.empty();
+
+      for(var id in workbooks) {
+        var tag = $('<option value="' + id + '">' + workbooks[id] + '</option>');
+        tag.appendTo(select);
+      }
+    },
+
+    init: function() {
+      // hack because of jQuery shenanigans
+      jQuery.event.props.push('dataTransfer');
+
+      $('body').bind('dragover', function(event) {
+        event.stopPropagation();
+        event.preventDefault();
+        event.dataTransfer.dropEffect = 'copy';
+      });
+
+      $('body').bind('drop', excelParser.handleFiles);
+
+      // when a new workbook is selected, do stuff!
+      $('#workbook').change(function(event) {
+        var select = $(event.target);
+        var output = latexOutput[select.val()];
+        $('#latex-output').val(output);
+      });
+    }
+  };
+
+  $(function() {
+    zip.workerScriptsPath = 'zip/';
+    excelParser.init();
+  });
+})(window.jQuery);
diff --git a/index.html b/index.html
index aa4aed1..c72045a 100644
--- a/index.html
+++ b/index.html
@@ -25,6 +25,9 @@
       <h1 class="title">excel => LaTeX</h1>
       <h4 class="info">Drag any .xlsx file onto the page to extract data and convert it into a LaTeX table</h4>
       <div class="content">
+        <label for="workbook">Workbook:</label>
+        <select id="workbook" name="workbook"></select>
+
         <textarea id="latex-output" readonly="readonly"></textarea>
         <p>Mostly untested, so if you find a bug or have a feature request, <a href="https://github.com/eric-wood/excel2latex/issues">let me know!</a>
         <p class="disclaimer">Note: this only works with .xlsx files. That means .xls files will <b>not</b> work.</p>
@@ -32,7 +35,7 @@
         <p>Lovingly hacked together by <a href="http://ericwood.org">Eric Wood</a></p>
       </div>
     </div>
-    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
+    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
     <script type="text/javascript" src="zip/zip.js"></script>
     <script type="text/javascript" src="converter.js"></script>
   </body>