Default Button for a page:
<form id="form1" runat="server" defaultbutton="buttonName"></form>
Default Button for a panel:
<asp:Panel runat="server" DefaultButton="lbHello"></asp:Panel>
Default in a div:-
<div onkeypress="javascript:return WebForm_FireDefaultButton(event, 'buttonID')"></div>
For Linkbutton to make a default page, add below javascript at the end of the page
<script type="text/javascript">
var __defaultFired = false;
function WebForm_FireDefaultButton(event, target) {
var element = event.target || event.srcElement;
if (!__defaultFired && event.keyCode == 13 && !(element && (element.tagName.toLowerCase() == "textarea"))) {
var defaultButton;
if (__nonMSDOMBrowser)
defaultButton = document.getElementById(target);
else
defaultButton = document.all[target];
if (defaultButton) {
if(typeof(defaultButton.click()) != "undefined")
defaultButton.click();
else
eval(unescape(defaultButton.href.replace("javascript:", "")));
event.cancelBubble = true;
if (event.stopPropagation) event.stopPropagation();
return false;
}
}
return true;
}
</script>