function $(id){
  return document.getElementById(id);
}
function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}
function checkEmail(email) {
  invalid = " /:,;";
  if(email == "") { return false }
  for(i=0; i < invalid.length; i++) {
    bad = invalid.charAt(i);
    if (email.indexOf (bad, 0) != -1) { return false }
  }
  at = email.indexOf("@", 0);
  if( (at == -1) || (at == 0) ) { return false }
  if(email.indexOf("@", at+1) != -1) { return false }
  period = email.indexOf(".", at);
  if( (period == -1) || (period == at+1) ) { return false }
  if(period+3 > email.length == -1) { return false }
  return true;
}
function checkObjForEmail(id, errMsg) {
  var result = false;
  var obj = $(id);
  if (obj) {
    var email = obj.value;
    if (email) {
      result = checkEmail(email);
      if(!result){
        obj.focus();
        obj.select();
        if (errMsg) { alert(errMsg) }
      }
    }
  }
  return result;
}
// sets focus in the first field in the first form ignoring form with id=formLogin
function setFormFocus() {
outerLoop:
  for(var i=0; i<document.forms.length; i++){
    for(var j=0; j<document.forms[i].elements.length; j++){
      if(document.forms[i].id!='formLogin' && (document.forms[i].elements[j].type=='text' || document.forms[i].elements[j].type=='textarea' || document.forms[i].elements[j].type=='password')){
        try {
          document.forms[i].elements[j].focus();
          document.forms[i].elements[j].select();
        } catch(err) {
        }

        break outerLoop;
      }
    }
  }
}
//addLoadEvent(setFormFocus);

/**
 * generuje losowy ciag tekstowy o zadanej dlugosci
 **/
function randomString(_length) {
	var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
	var string_length = _length;
	var randomstring = '';
	for (var i=0; i<string_length; i++) {
		var rnum = Math.floor(Math.random() * chars.length);
		randomstring += chars.substring(rnum,rnum+1);
	}
	return randomstring;
}