<script language=javascript>
function search_form()
{
var frmname = document.all.txt1.value;
var frms = document.getElementsByName(frmname);
if(frms.length>0)
alert("yes");
else
alert("no");
}
</script>
<body>
<form name="frm1">
<input type=text name="txt1">
<input type=button value="search" onclick="javascript:search_form();">
</form>
<body>
function search_form()
{
var frmname = document.all.txt1.value;
var frms = document.getElementsByName(frmname);
if(frms.length>0)
alert("yes");
else
alert("no");
}
</script>
<body>
<form name="frm1">
<input type=text name="txt1">
<input type=button value="search" onclick="javascript:search_form();">
</form>
<body>
//存在
}
else{
//不存在
}