ASP.NET中用js取CheckBoxList中值的方法实例

<!--关键字-->
    <div id="keywordsdiv" style="border: 2px solid #6fa1d9; display: none; position: absolute;
        top: 0px; left: 0px; width: 260px; height: 120px; z-index: 3; background-color: #eaf1fd;">
        <div style="width: 260px; height: 20px; background-color: #6fa1d9">
            <ul style="cursor: pointer; line-height: 20px;">
                <li style="float: right" onclick="getcheckvale()">[确定]</li><li style="float: right"
                    onclick="closeself()">[关闭]</li></ul>
        </div>
        <div>
            <asp:checkboxlist id="cblkeywords" runat="server" repeatcolumns="2">
            </asp:checkboxlist>
        </div>
    </div>

//打开关键词窗口
function  locking(e)
{     
    var divleft = e.offsetleft;
    var divtop = e.offsettop;
    while(e=e.offsetparent) 
    { 
         divleft   +=   e.offsetleft;   
         divtop   +=   e.offsettop; 
    }     
    var divobj = document.getelementbyid("keywordsdiv");  
    divobj.style.left = divleft+"px";
    divobj.style.top = divtop+20+"px";
    divobj.style.display = "block"; 
}
//关闭关键词窗口
function  closeself()
{
    document.all.keywordsdiv.style.display = 'none';
    var objcheck = document.getelementbyid("cblkeywords").getelementsbytagname("input");
    for (var i = 0; i < objcheck.length; i++) {
        document.getelementbyid("cblkeywords_" + i).checked = false;
    }
    return false;    
}
//关键词取值
function getcheckvale()
{
//var objcheck=document.getelementbyid("cblkeywords");
var objcheck=document.getelementbyid("cblkeywords").getelementsbytagname("input");
var objlabel = document.getelementbyid("cblkeywords").getelementsbytagname("label")
var txtkeywordsvalue = "";
var m=0
for(var i=0;i<objcheck.length;i++)
{
      if(document.getelementbyid("cblkeywords_"+i).checked)
      {
        var idcheck =document.getelementbyid("cblkeywords_"+i).id;//当前选择checkbox的id
        for(var j = 0;j <objlabel.length;j++)
        {
            var forvalue=objlabel[j].getattributenode("for").value             
            if(forvalue == idcheck)
            { 
               m+=1;
               for(var k=0;k<m;k++)
               {
               if(k==m-1)
               {
                    txtkeywordsvalue+=objlabel[j].innerhtml;
               }
               else
               {
                    txtkeywordsvalue +="|"+objlabel[j].innerhtml;
                    break;
                }
                }
            }
        }
      }    
}
document.getelementbyid("txtkeywords").value=txtkeywordsvalue;
document.all.keywordsdiv.style.display='none';
}

<asp:textbox id="txtkeywords" runat="server" readonly="true" class="inp"></asp:textbox>
<input id="imgkey" type="button" runat="server" onclick="locking(this)" class="tailbut"  value="选 择" />