Hello @kartik,
 Make the call on an input submit. Hopefully this code sample will get you started!
    <input type="submit" value="Submit" onclick"ValidatePage();" />
    <script type="text/javascript">
    function ValidatePage() {
        if (typeof (Page_ClientValidate) == 'function') {
            Page_ClientValidate();
        }
        if (Page_IsValid) {
            // do something
            alert('Page is valid!');                
        }
        else {
            // do something else
            alert('Page is not valid!');
        }
    }
</script>
Hope it helps!!
Thank You!!