ok my script is working fine but I must click Edit in full page in order to enable it to work properly.
here you are:
frappe.ui.form.on(“Contacto”, “validate”, function(frm) {
var value = frappe.model.get_value(‘Contacto’, frm.doc.name, ‘full_name’);
var pattern = /^[A-Za-z\s]+$/;
var result = pattern.test(value);
if (!pattern.test(value)) {
frappe.msgprint("Formato invalido para campo Contacto no incluye numeros");
validated = false;
}
});