function contact_callback() {
		
	// formulario de contacto

		$('#contacto').submit(function(){
			
			var form = $(this);
			
			if( checkCamposObligatorios(form.attr('id'), form.attr('required_msg')) )
			{
			// hide form
			
				form.slideUp(function(){
				
				// hide and empty popup window log
				
					$('#popup_window_log').hide().empty();
		
				// show loading image
				
					$('#popup_window_loading_image').fadeIn();
					
				// ajax call
				
					$.ajax({
						type: 'POST',
						url: form.attr('action'),
						data: getAjaxInputs(this),
						dataType: 'json',
						success: function(data){

						// hide loading image
						
							$('#popup_window_loading_image').fadeOut(function(){
								
							// set popup window log and show
						
								if( data.log.length > 0 ) {
									$('#popup_window_log').html("<ul><li>" + data.log.join("</li><li>") + "</li></ul>").slideDown();
								}
								
								if( data.error )
								{
								// show again the form 
								
									$('#contacto').slideDown();
								}
							});
						}
					});
					
				});

			}
		
			return false;
		});

	}