Modules & VBA :: Change HTML Text On Email If Checkbox Selected

I have the following code which works perfectly BUT I want to be able to add another line of text if users enable a checkbox. I have tried everything I can think of but can't get it to work. When using an "IF check150" statement it just adds the extra text in regardless of selection or not.

Code:

Function Mail_Radio_Outlook6(activedoc As String)
Dim OutApp As Object
Dim OutMail As Object
Dim strbody As String
Dim acc_req As String
Set OutApp = CreateObject("Outlook.Application")

[Code] ....

This is fine most of the time but If a user ticks check150 I want to add another paragraph.

Do I use an IF statement, if so in what format? is it a separate function etc?

I am slowly getting more familiar with Access but still come unstuck on the simplest of things at times.