function validate_form(form){
	var res=true;
	user_form=form;
	requiredStyleDefault("First_Name");
	requiredStyleDefault("Last_Name");	
	requiredStyleDefault("Email_Address");	
	requiredStyleDefault("Product_Purchased");	
	requiredStyleDefault("Date_Of_Purchase_Day");
	requiredStyleDefault("Place_Of_Purchase");
	
	requiredStyleDefault("Purchase_Receipt_Number");
	 
	 if(!validate_required_fields()) res=false;else
	 if(!validate_date())res=false;
	else if(!validate_email())res=false;
	 if(res){ 

	   user_form.submit();
	   document.getElementById("button_warranty").disabled=true;
	  }
} 
		function requiredStyleDefault(nameField){ 	
			if(document.getElementById(nameField).className.indexOf('required')>=0){
			 document.getElementById(nameField).className=document.getElementById(nameField).className.replace(/\brequired\b/,'');
			
			 }
		
		}   
      function requiredStyle(nameField,type){  
		if(document.getElementById(nameField).className.indexOf('required')<0){
	  		document.getElementById(nameField).className+=" required";
		}
		
		if(type=='email')
				document.getElementById("error_registration_div").innerHTML ="<div class='user_message_error'>Please insert a valid email</div>";   
		else if(type=='date')
			document.getElementById("error_registration_div").innerHTML ="<div class='user_message_error'>Please insert a valid date</div>";   
		else 
			document.getElementById("error_registration_div").innerHTML ="<div class='user_message_error'>Please complete the required fields</div>";   
	  
	  
	}
	function validate_required_fields(){ 	
	   var val=true;	  
	
	   if( user_form.First_Name.value.length == 0){  
	      requiredStyle("First_Name","");  
	      val=false;		  
		}
		if( user_form.Last_Name.value.length == 0){  
	      requiredStyle("Last_Name","");  
	      val=false;		  
		}
		if( user_form.Email_Address.value.length == 0){  
	      requiredStyle("Email_Address","");  
	      val=false;		  
		}
		if( user_form.Product_Purchased.value.length == 0){  
	      requiredStyle("Product_Purchased","");  
	      val=false;		  
		}
		if( user_form.Place_Of_Purchase.value.length == 0){  
	      requiredStyle("Place_Of_Purchase","");  
	      val=false;		  
		}
		if(user_form.Date_Of_Purchase_Day.value.length == 0){  
	      requiredStyle("Date_Of_Purchase_Day","");  
	      val=false;		  
		}
		
		if(user_form.Purchase_Receipt_Number.value.length == 0){  
	      requiredStyle("Purchase_Receipt_Number","");  
	      val=false;		  
		}
		
										
		  
	        return val; 
			
	}
	
	
	function validate_email(){ 	
		var email_error="";
	    var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;  
	    var address =user_form.Email_Address.value;   
		var val=true;  
		
		if(reg.test(address) == false) {
			  requiredStyle("Email_Address","email");   
	     
	      val=false;		  		  
		}
		return val;
	}
	
	
	
	
	
	function validate_date(){ 	
		var email_error="";	   
	    var date =user_form.Date_Of_Purchase_Day.value;   		
		var curr_date = new Date();
		
		
		var montharray=new Array(12);
	montharray["JAN"]="0";
	montharray["FEB"]="1";
	montharray["MAR"]="2";
	montharray["APR"]="3";
	montharray["MAY"]="4";
	montharray["JUN"]="5";
	montharray["JUL"]="6";
	montharray["AUG"]="7";
	montharray["SEP"]="8";
	montharray["OCT"]="9";
	montharray["NOV"]="10";
	montharray["DEC"]="11";
	
	dtCh ="-";
	var pos1=date.indexOf(dtCh);
	var pos2=date.indexOf(dtCh,pos1+1);
	var strDay=date.substring(0,pos1);
	var strMonthtemp=date.substring(pos1+1,pos2);
	var strMonth=montharray[strMonthtemp];
	var strYear=date.substring(pos2+1);
	strYr=strYear;
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1);
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1);
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1);
	}
	month=parseInt(strMonth);
	day=parseInt(strDay);
	year=parseInt(strYr);
	
	var myDate=new Date();
	myDate.setFullYear(year,month,day);
	
	
	var act	=new Date();
 	act.setFullYear(curr_date.getYear()+1900,curr_date.getMonth(),curr_date.getDate());
		var val=true;  
	
		if( act < myDate) {
	     requiredStyle("Date_Of_Purchase_Day","date");  
	      val=false;		  		  
		}
		else{
			 document.getElementById("Date_Of_Purchase_Day_converted").value = strYr+"-"+strMonth+"-"+strDay;
			
			}
		return val;
	}