function checkLForm(){
  var regForm=document.forms["lform"];
  var errorOccured=0;
  var errorMessage='';
  if (regForm.log_login.value.length<1 || regForm.log_pass.value.length<1){
    errorOccured=1;
    errorMessage=errorMessage+"Вы должны ввести логин и пароль!\n";
  }
  if (errorOccured==1){
    alert(errorMessage);
    return false;
  } else {
    return true;
  }
}

function PrintTags(start,end) {
  var clientPC = navigator.userAgent.toLowerCase();
  var clientVer = parseInt(navigator.appVersion);
  var is_ie = ((clientPC.indexOf("msie") != -1) && (clientPC.indexOf("opera") == -1));
  var is_win   = ((clientPC.indexOf("win")!=-1) || (clientPC.indexOf("16bit") != -1));
  if ((clientVer >= 4) && is_ie && is_win) {
    if (document.selection.createRange().text!=""){
      if (document.editform.text.value.indexOf(document.selection.createRange().text)!=-1){
          document.selection.createRange().text=start+document.selection.createRange().text+end;
      }
      else{
          document.editform.text.value+=start+end;
      }
    }
    else {
    document.editform.text.value+=start+end;
    }
  }
  else {
    document.editform.text.value+=start+end;
  }
}

function AddLink(mail) {
  var message=(mail)?("Введите адрес электронной почты:"):("Введите адрес в интернете:");
  var address=prompt(message,(mail)?(""):("http://"));
  if (address!=null){
      PrintTags("<a href=\""+((mail)?("mailto:"):(""))+address+"\">","</a>");
  }
}

function AddFontStyle(tag) {
  PrintTags("<"+tag+">","</"+tag+">");
}