//instancia o ajax
	function Inint_AJAX() {
	   try { return new ActiveXObject("Msxml2.XMLHTTP");  } catch(e) {} //IE
	   try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {} //IE
	   try { return new XMLHttpRequest();          } catch(e) {} //Native Javascript
	   alert("XMLHttpRequest not supported");
	   return null;
	};
	//valido o código do captcha
	function verifica(val) {
		 var req = Inint_AJAX();
		 req.onreadystatechange = function () { 
			  if (req.readyState==4) {
				   if (req.status==200) {
						if(req.responseText=="1")
						{
						//document.getElementById("security_code").style.border = '';
						$("#security_code").removeClass("error");
						//var aux1=validaCamposForm();
						document.getElementById("flag").value = true;
						}
						else
						
						{
						alert("Código de verificação inválido");
						//document.getElementById("security_code").style.border = 'solid 1px #812caf';
						$("#security_code").addClass("error");
						document.getElementById("security_code").focus();
						//return("errado");
						}
						//document.getElementById(src).innerHTML=req.responseText;
				   } 
			  }
		 };
		 req.open("GET", "includes/contato/contato_1/ajaxCaptcha.php?val="+val); 
		 req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=tis-620"); // set Header
		 req.send(null); 
		 if(document.getElementById("flag").value=="true")
		  return(true);
		 else
		  return(false);
	}

	function valida()
	{ 
		var captcha=document.getElementById("security_code").value;
		var aux = verifica(captcha);
		if(aux==true)
		{ return(true); }
		else
		{ return(false); }
	}