[Resolved] Problem with data-bound controls validation

[mf12]

Hello,

I'm currently working on a data entry application in VB.NET and I'm using data-bound controls by simply dragging the table from the Data Sources window onto the form. It's my first time doing this, but this will save me quite a bit of time since this table has plenty of fields.

Anyway, my problem is that when I enter an invalid value in a textbox and then delete the text it won't let me select other controls or even close the form!
For example, say I have an Age field in the DB, which is an int and I mistakenly type "," on its textbox. Then I decide I actually want to leave that field blank (considering it allows nulls) so I just delete all of the textbox's contents, after doing so, I'm not able to switch focus to another control or close the form.

Does anyone know how I can prevent this from happening?

Thanks in advance.