ผมอยากจะทำ ตัวหนา ตัวเอียง(BBCode) ไม่ติดมันติดอะไรครับ

<script language=JavaScript src="styles/bbcode1.js" type=text/javascript></script>	  

<script language=JavaScript type="text/javascript">
			

			function showimage()
			{
				document.images.icons.src = icon_urls[document.frmMain.txthis.icon.options[document.frmMain.txthis.icon.selectedIndex].value];
			}
			

				function bbc_highlight(something, mode)
				{
					something.style.backgroundImage = "url("+(mode ? "/images/bbcode/bbc_hoverbg.gif)" : "/images/bbcode/bbc_bg.gif)");
				}
			</script>

<a onclick="surroundText('', '', document.form.frmMain.txthis); return false;" href="javascript:void(0);"><IMG onmouseover="bbc_highlight(this, true);" title="ตัวหนา" style="BACKGROUND-IMAGE: url(/images/bbcode/bbc_bg.gif); MARGIN: 1px 2px 1px 1px" onmouseout="if (window.bbc_highlight) bbc_highlight(this, false);" height="22" alt="ตัวหนา" src="/images/bbcode/bold.gif" width="23" align="bottom" border="0"></a>			

<tr>
	<td>History</td>
	<td><textarea name="txthis" id="txthis" rows="50" cols="100"></textarea></td>
</tr>