var nm = document.getElementById("name");
var em = document.getElementById("email");
var ph = document.getElementById("phone");

function validateContactForm(){	
	if(nm.value == ""){
		alert("Please enter your name");
		nm.focus();
		return false;
	}
	else if(em.value == "" && ph.value == ""){
		alert("Please enter either your email or a phone number");
		em.focus();
		return false;
	}
	else if(ph.value == "" && !validEmail(em.value)){
		alert("Please enter a valid email address");
		em.focus();
		return false;
	}
	
	if(msg.value == msgDefaultValue)
		msg.value = "";
	
	return true;
}

var msgDefaultValue = "Please type your message here"
var msg = document.getElementById("message");
		msg.value = msgDefaultValue;
		msg.style.color = "#999";
		msg.onfocus = function(){
			if(msg.value == msgDefaultValue)
				msg.value = "";
			msg.style.color = "#000";
		}
		msg.onblur = function(){
			if(msg.value == ""){
				msg.value = msgDefaultValue;
				msg.style.color = "#999";
			}
		}

ph.onkeyup = validPhone;