Hi Ullas you can achieve this by jQuery.
Please refer the following snippet and you will get relevant ideas.
<div>
<asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine"/>
<asp:TextBox ID="TextBox2" runat="server" TextMode="MultiLine"/>
<asp:TextBox ID="TextBox3" runat="server" TextMode="MultiLine"/>
<asp:TextBox ID="TextBox4" runat="server" TextMode="MultiLine"/>
<asp:TextBox runat="server" TextMode="MultiLine"/>
<asp:Button ID="btnTest" Text="Test" runat="server" />
</div>
<script type="text/javascript">
$("[id*=btnTest]").live("click", function () {
var errorText = "";
try {
$("textarea").each(function () {
if (jQuery.trim($(this).text()) != "") {
var text = $(this).val();
$("textarea").not($(this)).each(function () {
if (text == jQuery.trim($(this).text())) {
errorText = "The text '" + text + "' appeared multiple times which is not allowed.";
throw "";
}
});
}
});
} catch (e) {
alert(errorText);
return false;
}
});
</script>
Thanks and Regards,
Rk_Hirpara