function submitenter(myfield,e)
{
var keycode;
if (window.event) keycode = window.event.keyCode;
else if (e) keycode = e.which;
else return true;

if (keycode == 13){
	return checkSearch(myfield.form);
}
else
	return true;
}

function checkSearch(){
	var chiave_reg_exp = /([a-zA-Z0-9])/;
	var chiave = $("#chiave").val();
	var fValid = true;

	if ((chiave==0) && (chiave=="")) {
		fValid = false;
	}
	
	if (chiave!=""){
		if (!chiave_reg_exp.test(chiave)){
			fValid = false;
		}
	}
	
	if (fValid) $("#ricerca").submit();

}