function verify()
{
  
  if(document.contactForm.name.value==""){
    alert("Please give your name. ");
    return false;  
  }else if(document.contactForm.phone.value==""){
    alert("Please enter your phone number. ");
    return false;
 }else if(!isEMailAddr(document.contactForm.email)){
    return false;
  }else if(document.contactForm.message.value==""){
    alert("Please enter your message. ");
    return false;
  }else{
    return true;
  }

}

function isEMailAddr(elem) {
        var str = elem.value;
    var re = /^[\w-]+(\.[\w-]+)*@([\w-]+\.)+[a-zA-Z]{2,7}$/;
    if (!str.match(re)) {
        alert("Verify the e-mail address format.");
        setTimeout("focusElement('" + elem.form.name + "', '" + elem.name + "')", 0);
        return false;
    } else {
        return true;
    }
}