function email_check(str) {

	var at="@";
	var dot=".";
	var lat=str.indexOf(at);
	var lstr=str.length;
	var ldot=str.indexOf(dot);
	
	if (str.indexOf(at)==-1){
	   return false;
	}
	
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   return false;
	}
	
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    return false;
	}
	
	 if (str.indexOf(at,(lat+1))!=-1){
	    return false;
	 }
	
	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    return false;
	 }
	
	 if (str.indexOf(dot,(lat+2))==-1){
	    return false;
	 }
	
	 if (str.indexOf(" ")!=-1){
	    return false;
	 }
	
	 return true;					
}

	
	contatoImgOver 			= new Image();
contatoImgOver.src 		= "/images/titulo_contato2.jpg";
contatoImg 			= new Image();
contatoImg.src 			= "/images/titulo_contato.jpg";

manualImgOver 			= new Image();
manualImgOver.src 		= "/images/titulo_manual2.jpg";
manualImg 			= new Image();
manualImg.src 			= "/images/titulo_manual.jpg";

downloadImgOver 		= new Image();
downloadImgOver.src 		= "/images/titulo_download2.jpg";
downloadImg 			= new Image();
downloadImg.src 		= "/images/titulo_download.jpg";

faqImgOver 			= new Image();
faqImgOver.src 			= "/images/titulo_faq2.jpg";
faqImg 				= new Image();
faqImg.src 			= "/images/titulo_faq.jpg";

registroImgOver 		= new Image();
registroImgOver.src 		= "/images/titulo_registro2.jpg";
registroImg 			= new Image();
registroImg.src 		= "/images/titulo_registro.jpg";

depoimentosImgOver 		= new Image();
depoimentosImgOver.src 		= "/images/titulo_depoimentos2.jpg";
depoimentosImg 			= new Image();
depoimentosImg.src 		= "/images/titulo_depoimentos.jpg";

cadastreseImgOver 		= new Image();
cadastreseImgOver.src 		= "/images/titulo_cadastrese2.jpg";
cadastreseImg 			= new Image();
cadastreseImg.src 		= "/images/titulo_cadastrese.jpg";

muralImgOver 			= new Image();
muralImgOver.src 		= "/images/titulo_mural2.jpg";
muralImg 			= new Image();
muralImg.src 			= "/images/titulo_mural.jpg";

function changeImageContato()
{
  document.images["contatoimg"].src= contatoImgOver.src;
  return true;
}

function changeImageBackContato() 
{
   document.images["contatoimg"].src = contatoImg.src;
   return true;
}

function changeImageManual()
{
  document.images["manualimg"].src= manualImgOver.src;
  return true;
}

function changeImageBackManual() 
{
   document.images["manualimg"].src = manualImg.src;
   return true;
}

function changeImageMural()
{
  document.images["muralimg"].src= muralImgOver.src;
  return true;
}

function changeImageBackMural() 
{
   document.images["muralimg"].src = muralImg.src;
   return true;
}

function changeImageDownload()
{
  document.images["downloadimg"].src= downloadImgOver.src;
  return true;
}

function changeImageBackDownload() 
{
   document.images["downloadimg"].src = downloadImg.src;
   return true;
}

function changeImageFaq()
{
  document.images["faqimg"].src= faqImgOver.src;
  return true;
}

function changeImageBackFaq() 
{
   document.images["faqimg"].src = faqImg.src;
   return true;
}

function changeImageRegistro()
{
  document.images["registroimg"].src= registroImgOver.src;
  return true;
}

function changeImageBackRegistro() 
{
   document.images["registroimg"].src = registroImg.src;
   return true;
}

function changeImageDepoimentos()
{
  document.images["depoimentosimg"].src= depoimentosImgOver.src;
  return true;
}

function changeImageBackDepoimentos() 
{
   document.images["depoimentosimg"].src = depoimentosImg.src;
   return true;
}

function changeImageCadastrese()
{
  document.images["cadastreseimg"].src= cadastreseImgOver.src;
  return true;
}

function changeImageBackCadastrese() 
{
   document.images["cadastreseimg"].src = cadastreseImg.src;
   return true;
}