dom=(document.getElementById)?true:false;
nn4=(document.layers)?true:false;
ie4=(!dom && document.all)?true:false;

function checkbox_check_all(c,n) {
 e=c.form.elements;
 for(i=0;i<e.length;i++)
  if(e[i].name==n+'[]') e[i].checked=c.checked;
 }

function checkbox_validator(f,name,confirmMsg,errMsg) {
 if(confirm(confirmMsg)) {
   e=f.elements;
   for(i=0;i<e.length;i++) if(e[i].name==name+'[]'&&e[i].checked) return true;
   alert(errMsg);
 }
 return false;
}

function select_validator(f,name,errMsg) {
 var i=f[name].selectedIndex;
 if(f[name].options[i].value!='0') return true;
 alert(errMsg);
 return false;
}

function common_validator(obj, chk_fields, errMsg) {
 for (i=0;i<obj.elements.length;i++) {
  if (chk_fields.indexOf('{'+obj.elements[i].name+'}') != -1 && (obj.elements[i].value == '') && obj.elements[i].type != 'hidden') {
   alert(errMsg);
   obj.elements[i].focus();
   return false;
  }
 }
 return true;
}

function f_empty(f,errMsg) {
 if (f.value=='' && f.type != 'hidden') {
  if (errMsg == '') {
   self.alert('Error: field <<'+f.name+'>> is empty');
  } else {
   self.alert(errMsg);
  }
  f.focus();
  return true;
 }
 return false;
}

function f_int(f,errMsg) {
 if (isNaN(parseInt(f.value))) {
  if (errMsg == '') {
   self.alert('Error: field <<'+f.name+'>> is not integer');
  } else {
   self.alert(errMsg);
  }
  f.focus();
  return false;
 }
 return true;
}

function f_float(f,errMsg) {
 if (isNaN(parseFloat(f.value))) {
  if (errMsg == '') {
   self.alert('Error: field <<'+f.name+'>> is not float');
  } else {
   self.alert(errMsg);
  }
  f.focus();
  return false;
 }
 return true;
}

// Replaces text with by in string
function str_replace(text,by,string) {
    var strLength = string.length, txtLength = text.length;
    if ((strLength == 0) || (txtLength == 0)) return string;
    var i = string.indexOf(text);
    if ((!i) && (text != string.substring(0,txtLength))) return string;
    if (i == -1) return string;
    var newstr = string.substring(0,i) + by;
    if (i+txtLength < strLength) newstr += str_replace(text,by,string.substring(i+txtLength,strLength));
    return newstr;
}


function setImg(imgID,imgName, imgUrl) {
         document.images[imgID].src = imgName ? eval(imgName + "Img.src") : imgUrl;
}