//funciones del script para la entrada en WebCT

function check_fields() {
  if (submitted) {
    return false;
  }
 // if (document.authenticate.WebCT_ID.value == "") {
  if (document.getElementById('webct1').value == "") {
    alert("Please enter a WebCT ID.");
    return false;
  }
  submitted = true;
  return true;
}

function getCookieVal (offset) {
  var cookie_data = document.cookie;
  var endstr = cookie_data.indexOf (";", offset);
  if (endstr == -1)
    endstr = cookie_data.length;
  return unescape(cookie_data.substring(offset, endstr));
};


function SetCookie (name,value,expires,path,domain,secure) {
  document.cookie = name + "=" + escape (value) +
    ((expires) ? "; expires=" + expires.toGMTString() : "") +
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    ((secure) ? "; secure" : "");
}

function GetCookie (name) {
  var cookie_data = document.cookie;
  var arg = name + "=";
  var alen = arg.length;
  var clen = cookie_data.length;
  var i = 0;
  while (i < clen) {
    var j = i + alen;
    if (cookie_data.substring(i, j) == arg)
      return getCookieVal (j);
    i = cookie_data.indexOf(" ", i) + 1;
    if (i == 0) break;
  }
  return null;
}

function GetValue (name, query_string) {
  if (name && query_string) {
    var arg = name + "=";
    var alen = arg.length;
    var clen = query_string.length;
    var i = 0;
    while (i < clen) {
      var j = i + alen;
      if (query_string.substring(i, j) == arg) {
        var endlen = query_string.indexOf("&", j);
        if (endlen == -1)
          endlen = query_string.length;
        return query_string.substring(j, endlen);
      }
      i = query_string.indexOf("&", i) + 1;
      if (i == 0) break;
    }
    return null;
  }
  return null;
}

function DeleteCookie (name,path,domain) {
  if (GetCookie(name)) {
    document.cookie = name + "=" +
      ((path) ? "; path=" + path : "") +
      ((domain) ? "; domain=" + domain : "");
  }
}



function contactar()
{
 var ancho_screen=screen.availWidth;
 var alto_screen=screen.availHeight;
 
 var ancho=(ancho_screen-375)/2;
 var alto=(alto_screen-200)/2;
 
 var opciones="left="+ancho+",top="+alto+",width=375,height=200"; 
 mi_ventana = window.open("contactar_uatd.html","",opciones); 
}


function Abrir_Ventana(el_url) {

var ancho=screen.availWidth-30;
var alto=screen.availHeight-160;
var titulo=""

window.open(el_url,titulo,"top=10,left=10,scrollbars=yes,resizable=yes,toolbar=yes,menubar=yes,location=yes,status=yes,width="+ancho+",height="+alto+"");
}

function ir_pagina(pagina)
{
 window.top.mainFrame.location=pagina;
}

function EsNumerico(sText)
{
   var ValidChars = "0123456789";
   var IsNumber=true;
   var Char;
 
   for (i = 0; i < sText.value.length && IsNumber == true; i++) 
      { 
      Char = sText.value.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
   
}