2 simple questions but still unsolved.

Question 1 : how do we open mdi child forms like modal ones ?

besides opening forms from the menu... there are some dialog box kind of forms.. which should be closed before returning back to its parent form... but it seems there is some problem in showing mdichild as modal... how do i solve it ??


Question 2 : formatting numbers in textbox ?

formatting numbers on lostfocus works.
but i want that whenever any text appears in that textbox..
it should appear formatted. means i need not lost focus it to make it to correct format.

MDI children cannot be shown modally, this is what happens when you try:

An unhandled exception of type 'System.InvalidOperationException' occurred in system.windows.forms.dll

Additional information: Forms that are not top level forms cannot be displayed as a modal dialog. Remove the form from any parent form before calling showDialog.

For #2 you could try using TextChanged, although if you change the text on a textchanged event (e.g. formatting) this will make the event handler trigger itself (bad).

For question 2:
You may try to format it on Textbox_Leave event and if not correct format return the focus to that.

the textbox is disabled...
i want that whenever any number appears it that it should be formatted only...

i need not leave the textbox for bringing it to correct format.

If it's disabled, then format the text before you assign it to TextBox.Text.

ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfSystemStringClassFormatTopic.htm

Rather than any event code for the textbox itself (if it's disabled there really shouldn't need to be any) put the formatting in whatever code actually sticks the value into the textbox.