function validateUsername() {
	var un = document.getElementById('txtUserID');
	var str = "";
	var userIdText = 'user id';
	var passwordText = 'password';
	var userError = 'Please enter your user id';
	if(un.value == str || un.value == userIdText) {
		alertBox();
		$("#alertEmpty").text(userError);
		//return error;
		return false;
		}
		
	else if ((un.value.length < 4) || (un.value.length > 10)) {
    	var error = "Your username must contain a minimum of 4 letters and a maximum of 10 letters.\n";
		alertBox();
		$("#alertEmpty").text(error);
		return false;
		}
	var pw = document.getElementById('txtPassword');
	var str = ""
	
	var passwordText = 'password';
	var pwError = 'Please enter your password.';
	if(pw.value == str || pw.value == passwordText) {
		alertBox();
		$("#alertEmpty").text(pwError);
		//return error;
		return false;
		}
	else {
		unpw();
		}
	}