So, just to confirm... Your question was:
>>I have two forms and I want one form to display in its Gridview, a data obtain from the combobox of the other form.
What I get from this is you have information in Form A that you want to use in Form B to populate further information with.
I provided you multiple links to references that deal explicitly with transferring information from one form to another but you say this doesn't help you.
Could you perhaps do a favour for those of us who aren't psychic and describe in more detail what you're trying to accomplish and in what way the links didn't help so people might have an idea of where to start then? :twisted:
In form B, how are you implementing the data call?
How are you referencing form A?
Is the information from form A available globally so that form B is able to see it? or is form B a child of form A?
Not to be picky here but you aren't providing any of the code that specifically shows in what ways you are attempting to derive your value from form A and in what ways it's being implemented into form B. You're also not showing the relationship between the forms or how the forms are instanciated (hmm... is that even a word? :twisted:) which might help others determine if there's a logic error somewhere in your coding or additional steps that might resolve your issue.