Dear Experts

I have a numeric type text box with following properties

Input 999-999
Formt z
Alignment left

When, without EXE, I write six digits then control goes to next textbox.
But when in EXE I write six digits then control "DO NOT" go to next textbox

and On pressing "ENTER" an other value appears, For example

If I write 229-021 and press Enter then 022-902 appears in it.

The width of textbox is 100 that can have more than SIX digits and there are

no codes in any method of it.

What is reason? I mean on completion, according to format, the control

immediately must go to next object.

Please help