function markWrongFields(){	
	var returnBool = true;
	var name = document.getElementById('name');
	var email = document.getElementById('email');
	var day = document.getElementById('day');
	var month = document.getElementById('month');
	var year = document.getElementById('year');
	var nights = document.getElementById('nights');
	var adults = document.getElementById('adults');
	var add6 = document.getElementById('add6');
	
	name.style.border='1px solid #aaa';
	email.style.border='1px solid #aaa';
	day.style.border='1px solid #aaa';
	month.style.border='1px solid #aaa';
	year.style.border='1px solid #aaa';
	nights.style.border='1px solid #aaa';
	adults.style.border='1px solid #aaa';	
	
	if ( name.value == "" ) {
        name.style.border='2px solid red'; 
        returnBool = false;       
    } 
	
    atPos = email.value.indexOf("@",1);
    periodPos = email.value.indexOf(".",atPos);
	if ( email.value == "" || atPos == -1 || periodPos == -1 ) {
        email.style.border='2px solid red'; 
        returnBool = false;        
    } 
 
	if (day.value == "" ) {
        day.style.border='2px solid red'; 
        returnBool = false;       
    } 
  
	if ( month.value == "" ) {
        month.style.border='2px solid red'; 
        returnBool = false;       
    } 
   
	if ( year.value == "" ) {
        year.style.border='2px solid red'; 
        returnBool = false;       
    }     
    
	if ( nights.value == "" ) {
        nights.style.border='2px solid red'; 
        returnBool = false;       
    } 
   
	if ( adults.value == "" ) {
         adults.style.border='2px solid red'; 
         returnBool = false;             
    }    
	if ( add6.value == "" ) {
         add6.style.border='2px solid red'; 
         returnBool = false;             
    }       
   
   return returnBool;
  }