The two options for the select multiselect mode move the of sample code to each other

2020-03-30 01:20:34
OfStack
As follows:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title> Headless document </title>
<script type="text/javascript">
function copyToList(from,to){

    var fromList=eval('document.forms[0].'+from);
    var toList=eval('document.forms[0].'+to);

    if(toList.options.length > 0 && toList.options[0].value == 'temp'){
            toList.options.length=0;
    }

    var sel=false;

    for(i = 0;i < fromList.options.length;i++){
        var current=fromList.options[i];
        if(current.selected){
            sel=true;
            if(current.value=='temp'){
                alert(' This item cannot be selected !');
                return;
            }
            txt=current.text;
            val=current.value;
            toList.options[toList.length]=new Option(txt,val);
            fromList.options[i]=null;
            i--;
        }
    }

    if(!sel) alert(' You haven't chosen any projects yet !');
}
function allSelect(){    
    var chsen=document.getElementById('chosen');
    //If the chsen list box is 0 or the first option value is 'temp'
    if(chsen.length && chsen.options[0].value=="temp")
        return;

    for(var i=0;i<chsen.length;i++){
            chsen.options[i].selected=true;
    }
//Get the data
 function getdata() {
            var List = document.forms[0].RoleList;
　　　　　　　//Gets a hidden text box object
            var roles = document.getElementById("TRoleList");
            roles.value = "";
            var s = "";
            if (List.length != 0) {
                for (i = 0; i < List.length; i++) {
                    s += List.options[i].value + ",";
                }
            }
            roles.value = s;
        }
}
</script>
</head>
<body>
<table border="0">
<form onSubmit="allSelect()">   
<tr>   
<td>   
<select name="possible" size="4" MULTIPLE width="200" style="width:200px">   
<option value="1"> Guangzhou, China, </option>
<option value="2"> Shanghai, China </option>
<option value="3"> Beijing, China </option>   
<option value="4"> Wuhan, China </option> 
</select>   
</td>   
<td><a href="javascript:copyToList('possible','chosen')"> Add to the right --><br>   
<br>
</a><a href="javascript:copyToList('chosen','possible')"><-- Add to the left </a></td>   
<td>   
<select name="chosen"   size="4" MULTIPLE  width="200"  style="width:200px;">   
<option value="temp"> Select your area from the left </option> 
</select>   
</td>   
</tr>
</form>   
</table>
<input type="button"  value=" submit "  onclick="allSelect()" />yle
<input type="text" style="display:none;" id="TRoleList">
</body>
</html>