function validar()
{
	var nom = document.form_contacto.nombre;
	var ciudad = document.form_contacto.ciudad;
	var mail = document.form_contacto.mail;
	var filter=/^.+@.+\..{2,3}$/;
	var info = document.form_contacto.info;
	
	if (!nom.value){
		alert("Your name and surname or the company name is required");
		nom.focus();
		return false;
	}
	if (!ciudad.value){
		alert("A correct city is required please")
		ciudad.focus();
		return false;
	}
	if (!filter.test(mail.value)){
		alert ("A valid e-mail adress is required please")
		mail.focus();
		return false;
	}
	if (!info.value){
		alert("Tell us about the information you need please");
		info.focus();
		return false;
	}
}