how do i use own html in pm show

[abramelin]

Today i realized when reading a pm on my site that vb uses the postbit template in private messages. How can i use my own html in private message show instead of my posbit template ?
i have found an area in pm_showpm template:

<if condition="$show['recipients']">

<tr>

 <td class="alt1"><if condition="$ccrecipients"><strong>$vbphrase[recipients]</strong>: $ccrecipients<br /></if><if condition="$bccrecipients"><strong>$vbphrase[recipients] <span class="smallfont">($vbphrase[bcc])</span></strong>: $bccrecipients</if></td>

</tr>

</if>

</table>

$postbit

<br />

<if condition="$show['receiptprompt']">

 <table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center" id="receipt">

 <tr>

  <td class="thead"><strong>$vbphrase[confirm_outstanding_receipt]</strong></td>

 </tr>

 <tr>

..............

what if i change the green variable to my own custom html ? is this related with what i want?