>Thanks for the reply, my problem shouldn't be related to the if-clause or the == mark, I tried to remove them but same error..
>
>i define and use them in a procedure:
>

>procedure MyProc
>  LOCAL MyString
>
>  ....
>  MyString=""
>  ....
>endproc
>

>
>>>For your reference:
>>>(1) Set it to a space doesn't work too
>>>(2) I also though it may because VFP dunno it's char type, so I tried
>>>MyString="xxx"
>>>MyString=""
>>>also not work..
>>
>>How and where did you define those varialbes?

It should be something else going on. There is nothing wrong in this particular piece of code.