function ValidationContactUs()
{
    var Name= document.getElementById("<%=txtName.ClientID%>").value;
    var Email= document.getElementById("<%=txtEmail.ClientID %>").value;
    var Message= document.getElementById("<%=txtMsg.ClientID %>").value;
    var AlertMessage="";
    if (Name=="")
    {
        AlertMessage=" -Provide Name \n";
    } 
    if (Email=="")
    {
        AlertMessage +=" -Provide Email \n";
    } 
    if (Message=="")
    {
        AlertMessage +=" -Provide Message";
    } 
    if(Name==""||Email==""||Message=="")
    {
        alert(AlertMessage);
        document.getElementById("<%=txtName.ClientID%>").focus();  
        return false;
    }
    else
    {
        var emailPat = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
        var emailid=document.getElementById("<%=txtEmail.ClientID %>").value;
        var matchArray = emailid.match(emailPat);
        if (matchArray == null)
        {
            alert("Invalid Email.");
            document.getElementById("<%=txtEmail.ClientID %>").value=""
            document.getElementById("<%=txtEmail.ClientID%>").focus();  
            return false;
        }         
    }
}