problem with javascript selection manipulation in ie

[Skier88]

I am writing a text editor with buttons that, when clicked, surround the selection with their tag then move the cursor to the end of the closing tag. The first part works everywhere I've tested, but I can't figure out how to move the cursor in IE. Googling turns up no shortage of seemingly related results, but I honestly can't make sense of them. Since I'm already manipulating the selection, it seems like a line or two of code should be able to move the cursor. Here's what I have now (variable ie is globally defined).

function tag(obj,tag)
{
var start,end,pos,range;
if (ie)
{
obj.focus();
range=document.selection.createRange();
if(range=='')
return false;
if (range.parentElement()!==obj)
return false;
if (typeof range.text==='string')
document.selection.createRange().text='['+tag+']'+range.text+'[/'+tag+']';
//ie cursor code goes here
}
else
{
start=obj.selectionStart;
end=obj.selectionEnd;
if(start===end)
{
obj.focus();
return false;
}
obj.value=obj.value.substring(0,start)+'['+tag+']'+obj.value.substring(start,end)+'[/'+tag+']'+obj.value.substring(end);
obj.focus();
pos=end+tag.length*2+5;
obj.setSelectionRange(pos,pos);
}
return false;
}

Thanks for reading.

[Dijkgraaf]

As this site has code that achieves that, look at how they do it. In particular the function insert_text