Display validation message using ASP.Net CustomValidator in JavaScript

Hi nauna,

Refer below sample.

HTML

<script type="text/javascript">
    function CheckForHardCodedValue(source, arguments) {
        var tID = document.getElementById('<%= TextBox1.ClientID %>');
        var lID = document.getElementById('<%= Label2.ClientID %>');
        var lbl = document.getElementById('<%= Label10.ClientID %>');
        if (parseFloat(document.getElementById("TextBox1").value) >= parseFloat(document.getElementById("Label2").innerHTML)) {
            arguments.IsValid = true;
            document.getElementById("Label10").innerHTML = document.getElementById("TextBox1").value;
        }
        else {
            arguments.IsValid = false;
        }
    }
</script>
<div>
    <asp:TextBox runat="server" ID="TextBox1" />
    <br />
    <asp:Label ID="Label2" runat="server" Text="50" />
    <br />
    <asp:Label ID="Label10" runat="server" />
    <asp:CustomValidator ID="custome1" runat="server" ControlToValidate="TextBox1" ClientValidationFunction="CheckForHardCodedValue"
        ErrorMessage="TextBox Value Should be Greater that label value" ForeColor="Red"></asp:CustomValidator>
</div>

Screenshot