function checkSearch(theForm) {
	var chiave_reg_exp = /[a-zA-Z0-9]/;
	var sValid = true;

	if ((theForm.chiave.value==0) && (theForm.chiave.value.length<=1)) {
		sValid = false;
	}
	else if (!chiave_reg_exp.test(theForm.chiave.value)){
		sValid = false;
	}
	return sValid;
}