代码如下：
<SCRIPT LANGUAGE="JavaScript"> <!-- Begin function moveOver() { var boxLength = document.choiceForm.choiceBox.length; var selectedItem = document.choiceForm.available.selectedIndex; var selectedText = document.choiceForm.available.options[selectedItem].text; var selectedValue = document.choiceForm.available.options[selectedItem].value; var i; var isNew = true; if (boxLength != 0) { for (i = 0; i < boxLength; i++) { thisitem = document.choiceForm.choiceBox.options[i].text; if (thisitem == selectedText) { isNew = false; break; } } } if (isNew) { newoption = new Option(selectedText, selectedValue, false, false); document.choiceForm.choiceBox.options[boxLength] = newoption; } document.choiceForm.available.selectedIndex=-1; } function removeMe() { var boxLength = document.choiceForm.choiceBox.length; arrSelected = new Array(); var count = 0; for (i = 0; i < boxLength; i++) { if (document.choiceForm.choiceBox.options[i].selected) { arrSelected[count] = document.choiceForm.choiceBox.options[i].value; } count++; } var x; for (i = 0; i < boxLength; i++) { for (x = 0; x < arrSelected.length; x++) { if (document.choiceForm.choiceBox.options[i].value == arrSelected[x]) { document.choiceForm.choiceBox.options[i] = null; } } boxLength = document.choiceForm.choiceBox.length; } } function saveMe() { var strValues = ""; var boxLength = document.choiceForm.choiceBox.length; var count = 0; if (boxLength != 0) { for (i = 0; i < boxLength; i++) { if (count == 0) { strValues = document.choiceForm.choiceBox.options[i].value; } else { strValues = strValues + "," + document.choiceForm.choiceBox.options[i].value; } count++; } } if (strValues.length == 0) { alert("您没有选择任何内容"); } else { alert("您选择的内容如下:\r\n"+"第" + strValues+"条"); } } // End --> </script> <center> <form name="choiceForm"> <table border=0> <tr> <td valign="top" width=175> <div align="center">可选内容:<br> <select name="available" size=10 onchange="moveOver();"> <option value="1">内容一</option> <option value="2">内容二</option> <option value="3">内容三</option> <option value="4">内容四</option> <option value="5">内容五</option> <option value="6">内容六</option> <option value="7">内容七</option> <option value="8">内容八</option> <option value="9">内容九</option> <option value="10">内容十</option> </select> </div> </td> <td valign="top"> <div align="center">你的选择:<br> <select multiple name="choiceBox" style="width:175;" size="10"> </select> </div> </td> </tr> <tr> <td colspan=2 height=10> <div align="center"> <input type="button" value="删除" onclick="removeMe();"> <input type="button" value="结果" onclick="saveMe();"> </div> </td> </tr> </table> </form> </center>