Hello,
For RadCombobox you do it following way.
<script language="javascript" type="text/javascript">
function OnClientSelectedIndexChanged(sender, eventArgs) {
var item = eventArgs.get_item();
if (item.get_text() === "SOME VALUE") {
var btn = document.getElementById("YOUR BUTTON ID");
btn.className = 'show_button';
}
}
</script>
<telerik:radcombobox
id="RadComboBox1"
runat="server"
onclientselectedindexchanged="OnClientSelectedIndexChanged">
</telerik:radcombobox>l;
Your button will be initially hidden. This can be easily achieved by applying a CSS rule. When user selects a value you then apply a new CSS Rule which makes it visible. Following samples shows the CSS rules.
<style type="text/css">
.hidden_button { visibility: hidden; }
.show_button { visibility: visible; }
</style>
Regards,