// JavaScript Document
	
	var k = 0;
	
	$(document).ready(function () {  
		
		var speed = 10000;   
		var run = setInterval('cambiar()', speed);      
		 		
	}); 
	
	function cambiar() {    
		 		  
		var imagenes = new Array();
		imagenes[0] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo1.jpg)";
		imagenes[1] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo2.jpg)";
	   	imagenes[2] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo3.jpg)";
	    imagenes[3] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo4.jpg)";
	 	imagenes[4] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo5.jpg)";
		imagenes[5] = "url(http://www.upchiapas.edu.mx/2010/fondos/fondo6.jpg)"; 
						 		 		 
		var imagen = imagenes[k];
		      
		$("body").css("background-image", imagen); 
		$("body").css("background-repeat", "no-repeat"); 
		$("body").css("background-position", "top right");   
		
		k++;
		
		if(k == 6)
			k = 0;
		  
	}//cambiar   
	
	function buscar_limpiar(){
	 	var form = document.buscar;
		var objTxt = form.words;
		
		if(objTxt.value == 'Buscar...')
			objTxt.value = '';
		
	}//buscar_limpiar
	
	function buscar_txt(){
		var form = document.buscar;
		var objTxt = form.words;
		
		if(objTxt.value == '')
			objTxt.value = 'Buscar...';
		
	}//buscar_txt
	
	function cambiar_color(no,color){
		$("#bordeImg" + no).css("border-color", color);
	}//cambiar_color
	
	function verificar_contacto(){
		var form = document.contacto;
		
		if(form.nombre.value == ""){
			alert("Escriba el nombre");
			return false;		
		}//if		
				
		if(form.email.value == ""){
			alert("Escriba el email");
			return false;		
		}//if
		
		if(!validar_email(form.email.value)){
			alert("Escriba un email válido");
			return false;		
		}//if
		
		if(form.comentario.value == ""){
			alert("Escriba el comentario");
			return false;		
		}//if
	
		form.submit();
	
	}//verificar_contacto	
	
	function validar_email(email){
	
		var patron = new RegExp(/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i);
		if(email.search(patron) == 0){
			return true;
		}else{
			return false;
		}//
	
	}//valida_email