Wysiwyg help

i have this code

function blockformat(tag) {
	if(document.selection){ 
		var Editor = document.getElementById('iView').contentWindow.document;
		var range = Editor.selection.createRange();
		if (range.pasteHTML) {
			var content=Editor.selection.createRange().htmlText;
			content1="<"+tag+">"+content+"</"+tag+">";
			range.pasteHTML(content1);
		} 
	}  else if (window.getSelection) { 
		var Editor = document.getElementById('iView').contentWindow;
		var range = Editor.getSelection().getRangeAt(0);
		content1="<"+tag+">"+range+"</"+tag+">";
		getIFrameDocument('iView').execCommand('insertHTML',false, content1);
	}
}

the code get tag like “div” and insert into my wysiwyg the text that marked between the got tags.

to example
blockformat(‘div’);

not in my wysiwyg iframe there is " <div>blabla</div>"
now i want that if i clicked again
the tags are remove
like a
execcommand
if i click bold one time its make the text bold and second time its remove the bold

tnx …