Compiling English for your Boss
TI-BASIC, 77 - 34 (error text) = 43
In case he wants to do in on his TI-83/84 calculator ;)
As standard for functions, file string should be in Ans so it can return and display the output.
Ans-&gt;Str1:If 1=inString(Ans,&quot;A
Then:&quot;B
Else:&quot;A
End:Disp &quot;ERROR ON LINE 1&quot;,&quot;'&quot;+Ans+sub(Str1,2,-1+length(Str1))+&quot;'&quot;,&quot; ^ INVALID

Note that many tokens are one byte.