<script type="text/javascript" language="javascript">
function Callform(strid)
{
var textbox1_id =document.getElementById('textbox1');
var textbox1_txt =textbox1_id.value;
var content = document.getElementById("div1").innerHTML;
alert(content);
}
</script>
<form id="form1" runat="server">
<div id="div1">
<input id="Button1" onclick="javascript:Callform('form1')" runat="server" type="button" />
</div>
</form>