Conditional formatting in continuous forms

[LizaHawk]

I have a drop down box on a continuous form called (cmbItem)
When the users choose Option 6 (Other) and on the open event I wish to show another field txtOther which allows the user to give a description of what 'other' means but I only want to show the field for that record. (the user could potentially have more than one record as other)
Using conditional formatting I have managed to change the colours of the box so that the background is the same colour as the form unless other is chosen when it reverts to white. However I can't do the same with the border as this is not one of the options provided.
I need to use VBA but I am struggling to use the formatcondtions.add
Any help would be very appreciated.
I am now on week 3 of this problem and getting nowhere fast:banghead:

 

[SteveH2508]

Would enabling/disabling the textbox be acceptable?

You could then use conditional formatting without the need for VBA.

 

[LizaHawk]

Its a matter of aesthetics and consistency.
I think I really need to use the format conditions VBA code, but the information online is sketchy and so far I haven't been able to get it to work.