function isEmpty(obj){for(var i=0,j=obj.value,z;i<j.length;i++){z=j.substring(i,i+1);if(z!=' '){return(false);}}return(true);}
function notLen(obj,l){var i=obj.value; if(l>i.length) return(true);return(false)}
function notDate(obj){var i,j;if(isNaN(i=new Date(obj.value))) return(true);j=obj.value.split('/');if((1+i.getMonth())!=j[1]) return (true);return(false);}
function notNumber(obj){var i=parseInt(obj.value);if(isNaN(i)){return(true);}return(false);}
function notChecked(obj){if (obj.length>0)	for(var i=0;i<obj.length;i++){if(obj[i].checked)return(false);}else if(obj.checked) return(false);return(true);}
function notMail(obj){var reg=/\S+\.*\S+@\S+\.\w{2,3}\.*\S*/;if(obj.value.search(reg)==-1){return(true);}return(false);}
function notCombo(obj){if(obj.selectedIndex==0){return(true);}return(false);}
function notGSM(obj){var i=parseInt(obj.value);if(obj.value.substring(0,1)=='0'){return(true);} if(isNaN(i) || (obj.value.length<9) || (obj.value.length>10)){return(true);}return(false);}

//verifica il tipo e fa l'azione giusta
function notFld(fld) {   
  var i   
	if(fld.type)i=fld.type;
	else i=fld[0].type;
	switch (i){
	case "checkbox" :
	case "radio" :
		return notChecked(fld);
	break;
	case "select-one" :
	case "select-multiple":
		return notCombo(fld);
	break;
	case "text":
	case "hidden":
		return isEmpty(fld)
	break;
	default : 
		return false
	}
}