function createRequestObject(){ 
      var peticion; 
      var browser = navigator.appName; 
            if(browser == "Microsoft Internet Explorer"){ 
                  peticion = new ActiveXObject("Microsoft.XMLHTTP"); 
            }else{ 
                  peticion = new XMLHttpRequest(); 
} 
return peticion; 
} 
  
  
var http = new Array(); 
function ObtDatos(url){ 
      var act = new Date(); 
      http[act] = createRequestObject(); 
      http[act].open('get', url); 
      http[act].onreadystatechange = function() { 
      if (http[act].readyState == 4) { 
            if (http[act].status == 200 || http[act].status == 304) { 
  var texto 
texto = "<p class='comprobacion'>"+http[act].responseText+"</p>" 
                    var DivDestino = document.getElementById("DivDestino"); 
                    DivDestino.innerHTML = texto; 
                   
} 
} 
} 
http[act].send(null); 
} 


function compUsuario(Tecla) { 
	
     Tecla = (Tecla) ? Tecla: window.event; 
     input = (Tecla.target) ? Tecla.target : 
     Tecla.srcElement; 
     if (Tecla.type == "keyup") { 
          var DivDestino = document.getElementById("DivDestino"); 
          DivDestino.innerHTML = "<div></div>"; 
          if (input.value) { 
               ObtDatos("../processors/web_exist.php?q=" + encodeURIComponent(input.value)); 
          } 
     } 
}