function comprova(){
	var camps = document.getElementsByTagName('input');
	var sense = true;
	for (var i = 0; i < camps.length; i++){
	  var capa = camps[i].name+"capa";	  	
	  if(camps[i].title=='txt'){					
		  if(camps[i].value == ""){			  
			  document.getElementById(capa).innerHTML = "<img src='img/error.gif' border=0>&nbsp;El camp <b>"+camps[i].name+"</b> és obligatori";				
			  camps[i].focus();
			  sense = false;			  			    
	    }else{
	    	document.getElementById(capa).innerHTML = "";				
	    }		 	    
    }
    if(camps[i].title=='email'){	    		    	
	    if(document.form1.email.value.indexOf('@')==-1||document.form1.email.value.indexOf('.')==-1||document.form1.email.value.length<6){ 
	      document.getElementById('emailcapa').innerHTML = "<img src='img/error.gif' border=0>&nbsp;El valor del camp <b>email</b> és incorrecte";					  	
	  	  sense = false;
	    }else{
	    	document.getElementById('emailcapa').innerHTML = "";					  	
	    }	    	
	  }   
  } 
   if(sense == false){
  	altura();
  	if (n){
  		document.getElementById('elem1').style.top=2;
  	}
  	if (iex){
  		elem1.style.pixelTop=1;
  	}
  	return (false);

  }else{
  	document.form1.submit();
  }
}