Hello,

You can validate at OnEditingFormSave clientside event. Below is the snippet code. Hope this helps.

 function WebScheduler1_OnEditingFormSave(controlId, action, eventView)
        {
            var s = ISGetObject(controlId);
            var editWindow = s.GetEditingFormWindow();
            var wcCategories = editWindow.ISGetObject("wcCategories");
            if (wcCategories.Values == null)
            {
                alert("Categories can not be Empty");
                return false
            } else
            {

                return true;
            }
        }

Regards,
Handy

Since I have Multiselect disabled I modified the code to look at value instead of values and it works fine...Thanks

function WebScheduler1_OnEditingFormSave(controlId, action, eventView)
        {
            var s = ISGetObject(controlId);
            var editWindow = s.GetEditingFormWindow();
            var wcCategories = editWindow.ISGetObject("wcCategories");
            if (wcCategories.Value == "")
            {
                alert("Categories can not be Empty");
                return false
            } else
            {

                return true;
            }
        }

Hello Tim,

My previous code showed default categories in multiple selection. Your code for single selection is already correct. So, I think you will not find any problem in handle the validation.

Regards,
Handy