I'm working in VB.net 2013. I have a grid control that has a dropdown combobox in two of the cols. I load them from a string collection and the values can only be 4 digits long. I am loading the box just fine, but I don't want the user to be able to type a value greater then 4 digits and what i'd really like is for them to only type values that fall between the values that are in my string collection that i set up the choice list from. So for example. Right now say my low value in the dropdown is 5000 and the high is 9999. Now they can type 99999983484848484 or whatever number greater then 4 digits. I want them to be able to only type 4 digits and then stop them. I've set the maxlength to 4 and that doesn't seem to do anything.