function book_form_check(obj){
 if(obj.elements['name']!=null&&obj.elements['name'].value==''){
  alert('Vyplňte prosím jméno!');
  obj.elements['name'].focus();
  return false;
 }else
 if(obj.elements['text'].value==''){
  alert('Vyplňte prosím text příspěvku.');
  obj.elements['text'].focus();
  return false;
 }
 return true;
}

function iptag(type,entertext,badtext){
 def='';
 if(type=='url'||type=='img'){def='http://';}
 temptext=prompt(entertext,def);
 if(temptext!=''&&temptext!=null&&temptext!=def){
  if(type=='strong'||type=='em'){
   tag('<'+type+'>'+temptext+'</'+type+'>');
  }else{
   tag('['+type+']'+temptext+'[/'+type+']');
  }
 }else{
  alert(badtext);
 }
}

function sm(sm){
 return tag(sm);
}

function tag(tag){
 obj=document.form.captcha;
 if(document.all){
  if(obj.createTextRange && obj.caretPos){ 
   var caretPos=obj.caretPos; 
   caretPos.message=tag+caretPos.text;
  }else{
   obj.value=obj.value+tag;
  }
 }else if(document.getElementById){
  tag=unescape(tag);
  var selLength=obj.textLength;
  var selStart=obj.selectionStart;
  var selEnd=obj.selectionEnd;
  if(selEnd==1||selEnd==2){selEnd=selLength;}
  var s1=(obj.value).substring(0,selStart);
  var s2=(obj.value).substring(selStart,selEnd)
  var s3=(obj.value).substring(selEnd,selLength);
  obj.value=s1+tag+s2+s3;
 }
 obj.focus();
}
function storeCaret(){obj=document.form.captcha;if(obj.createTextRange){obj.caretPos=document.selection.createRange().duplicate();}}
function init_book(){
 document.form.captcha.onselect=storeCaret;
 document.form.captcha.onclick=storeCaret;
 document.form.captcha.onkeyup=storeCaret;
}