function formValidator(){
	
	var name = document.getElementById('dname');
	var phone = document.getElementById('phone');
	var email = document.getElementById('email');
	var message = document.getElementById('dtext');

	if(notEmpty(name,"Please enter your name")){
	if(notEmpty(message,"Please enter any query")){
	if(notEmpty(phone,"Please enter your phone number")){
	if(notEmpty(email,"Please enter your email address")){
     if(isNumeric(phone, "Please enter a valid phone number")){
	if(lengthRestriction(phone, 9, 12)){
	if(emailValidator(email, "Please enter a valid email address")){
							return true;
						}
					}
				}
			}
		
	    }
    }	
	}
	return false;
	
}

function notEmpty(elem, helperMsg){
	if(elem.value.length == 0){
		alert(helperMsg);
		elem.focus(); // set the focus to this input
		return false;
	}
	return true;
}

function isNumeric(elem, helperMsg){
	var numericExpression = /^[0-9]+$/;
	if(elem.value.match(numericExpression)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}

function lengthRestriction(elem, min, max){
	var uInput = elem.value;
	if(uInput.length > min && uInput.length < max){
		return true;
	}else{
		alert("Please enter a 10 digit phone number");
		elem.focus();
		return false;
	}
}


function emailValidator(elem, helperMsg){
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	if(elem.value.match(emailExp)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}