function comprobar(){
	var Comprobacion = true;
	for (var i = 0; i < document.getElementById('formulario').elements.length; i++)
	{	
       if ((document.getElementById('formulario').elements[i].type == "text") && (document.getElementById('formulario').elements[i].name != "observaciones"))
	   {
	     if (document.getElementById('formulario').elements[i].value == "")
		 {
		    document.getElementById('formulario').elements[i].style.background = "#B61F33";
			//document.getElementById('formulario').elements[i].value = "Introduzca el campo";
			Comprobacion = false;
	     }
		 else document.getElementById('formulario').elements[i].style.background = "#F9A350";
	   }
    }
	
	// Comprobamos el primer email
	if ((Comprobacion) && (!isEmailAddress(document.getElementById('email').value)))
	{
	   document.getElementById('email').style.background  = "#B61F33";
	   Comprobacion = false;
	}
	
	// Enviamos el mensaje
	if (Comprobacion)
	{
	  //document.getElementById('formulario').submit();
	  return true; 
	}
	else{
		alert("Introduzca los datos sombreados en rojo");
		return false;
	}
}

function isEmailAddress(theElement)
{
  var s = theElement;
  var filter=/^[A-Za-z][A-Za-z0-9_]*@[A-Za-z0-9_]+\.[A-Za-z0-9_.]+[A-za-z]$/;
  if (s.length == 0 ) return true;
  if (filter.test(s)) return true;
  return false;
}

function change(theelement){
	theelement.style.background = "#F9A350";	
}