function validate(){
	var thisform 		= xbGetElementsByNameAndType("estimate", "forms")[0];
	var firstname		= thisform.First_Name.value;
	var lastname		= thisform.Last_Name.value;
	var city			= thisform.City.value;
	var daytimephone	= thisform.Daytime_Phone.value;
	var nighttimephone	= thisform.Evening_Phone.value;
	
	
	
	
	//if not nn4.7, then clear all the error displays
	if(!(navigator.family == "nn4")){
		var firstnameerror 							= xbGetElementById('firstnameerror');
    	var firstnameerrorstyle 					= new xbStyle(firstnameerror);
			firstnameerrorstyle.setInnerHTML("");
			
		var lastnameerror 							= xbGetElementById('lastnameerror');
    	var lastnameerrorstyle 						= new xbStyle(lastnameerror);
			lastnameerrorstyle.setInnerHTML("");
		
		var cityerror 								= xbGetElementById('cityerror');
    	var cityerrorstyle 							= new xbStyle(cityerror);
			cityerrorstyle.setInnerHTML("");
	
		
	
		var daytimephoneerror 						= xbGetElementById('daytimephoneerror');
    	var daytimephoneerrorstyle 					= new xbStyle(daytimephoneerror);
			daytimephoneerrorstyle.setInnerHTML("");
			
		var nighttimephoneerror 						= xbGetElementById('nighttimephoneerror');
    	var nighttimephoneerrorstyle 					= new xbStyle(nighttimephoneerror);
			nighttimephoneerrorstyle.setInnerHTML("");
			
	}
	
	//Check firstname for valid input
	if(firstname == ""){
		if(navigator.family == "nn4"){
			alert("Please enter your first name");
			thisform.First_Name.focus();
		}else{
			firstnameerrorstyle.setInnerHTML("<b>&nbsp;<< Required<b>");
			thisform.First_Name.value="";
			thisform.First_Name.focus();
		}
		return false;
	}
	
	//Check lastname for valid input
	if(lastname == ""){
		if(navigator.family == "nn4"){
			alert("Please enter your last name");
			thisform.Last_Name.focus();
		}else{
			lastnameerrorstyle.setInnerHTML("<b>&nbsp;<< Required<b>");
			thisform.Last_Name.value="";
			thisform.Last_Name.focus();
		}
		return false;
	}
	
	//Check city for valid input
	if(city == ""){
		if(navigator.family == "nn4"){
			alert("Please enter your city");
			thisform.city.focus();
		}else{
			cityerrorstyle.setInnerHTML("<b>&nbsp;<< Required<b>");
			thisform.City.value="";
			thisform.City.focus();
		}
		return false;
	}
	
	
	//Check for valid phone number
	if(checkPhoneNumber(daytimephone) == false){
		if(navigator.family == "nn4"){
			alert("Please enter a valid phone number");
			thisform.Daytime_Phone.focus();
		}else{
			daytimephoneerrorstyle.setInnerHTML("<b>&nbsp;<< Required<b>");
			thisform.Daytime_Phone.value="";
			thisform.Daytime_Phone.focus();
		}
		return false;
	}
	
	//Check for valid phone number
	if(checkPhoneNumber(nighttimephone) == false){
		if(navigator.family == "nn4"){
			alert("Please enter a valid phone number");
			thisform.Evening_Phone.focus();
		}else{
			nighttimephoneerrorstyle.setInnerHTML("<b>&nbsp;<< Required<b>");
			thisform.Evening_Phone.value="";
			thisform.Evening_Phone.focus();
		}
		return false;
	}	
	
	
	
	
	return true;
	
}

function checkPhoneNumber(phoneNo) {  
	var phoneRE = /^\d{3}-\d{3}-\d{4}$/;  
	if (phoneNo.match(phoneRE)){    
		return true; 
	}else{    
		alert("The phone number entered is invalid! \nPlease enter the phone number with the following format: xxx-xxx-xxxx");    
		return false;  
	}
}