Edit in JSFiddle

function ValidateEmail(email) {
        // Validate email format
        var expr = /^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
        return expr.test(email);
    };

$("#Click").live("click", function () {
        if (!ValidateEmail($("#txtEmail").val())) {
            $("#errmsg").html("Invalid Email Address!").show().fadeOut("slow");
               return false;
        }
        else {
             $("#errmsg").html("Valid Email Address!!").show().fadeOut("slow");
               return false;
        }
    });

 <script type = "text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
 <input type = "text" id = "txtEmail" />
<input type = "button" id = "Click" value = "Click" />
<span id="errmsg"></span>

#errmsg
{
color: red;
}