function validate(nm, eml, msg, ph) {
    var name = document.getElementById(nm);
    var email = document.getElementById(eml);
    var message = document.getElementById(msg);
    var phonenumber = document.getElementById(ph);
    if (name.value == "") {
        alert("please enter your name..!");
        name.focus();
        return false;
    }
    if (email.value == "") {
        alert("please enter Email address..!");
        email.focus();
        return false;
    }
    var emailRe = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*\.(\w{2}|(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum))$/
    var phoneRe = /^((\+\d{1,3}(-| )?\(?\d\)?(-| )?\d{1,5})|(\(?\d{2,6}\)?))(-| )?(\d{3,4})(-| )?(\d{4})(( x| ext)\d{1,5}){0,1}$/
    // var phoneRe=/^\d{10}(-)/         
    if (!emailRe.test(email.value)) {
        alert('Email address is invalid');
        return false;
    }
    if (phonenumber.value != "") {
        if (!phoneRe.test(phonenumber.value)) {
            alert('Phone number is invalid');
            return false;
        }
    }
    if (message.value == "") {
        alert("please enter your message..!");
        message.focus();
        return false;
    }
}