js option删除代码集合

1、 JavaScript

var oSel=document.form1.DropDownCity; 
while(oSel.options.length>0){ 
oSel.removeChild(oSel.options[0]); 
}

2、 JavaScript

<SCRIPT LANGUAGE="JavaScript"> 
function del1(){ 
var obj = document.getElementById("s"); 
var count = obj.options.length; 
for(var i = 0;i<count;i++){ 
obj.options.remove(0);//每次删除下标都是0 
} 
} 
</SCRIPT>

3、 JavaScript

<script language="javascript"> 
function del() { 
for (var i = s.options.length - 1; i >= 0; i --) 
s.options[i] = null; 
} 
</script>

4、 JavaScript

<SCRIPT LANGUAGE="JavaScript"> 
function del1(){ 
var obj = document.getElementById("s"); 
obj.options.length=0 
} 
</SCRIPT>