I know this should be really simple but I'm having trouble figuring out the logic.

I have a form that can create scheduled tasks. To create the task the user must complete 3 different sections

Days of Week
Days of Month
Task Command Line

For the Days of Week and Days of Month there are various checkboxes they can check and I assign an Integer to the Tag property of each one.

The Task Command line is a simple textbox

Now, when they click the CREATE TASK button I want to check that they have selected at least one checkbox in the Days of Week and Days of Month sections as well as entered a command line

I was doing this before

Code:
        For Each Ctrl As Control In Me.GroupBox_DaysofMonth.Controls
            If TypeOf Ctrl Is CheckBox AndAlso DirectCast(Ctrl, CheckBox).Checked Then
                DaysOfMonthValue = DaysOfMonthValue + CInt(DirectCast(Ctrl, CheckBox).Tag.ToString)
            End If
        Next

        For Each Ctrl As Control In Me.GroupBox_DaysofMonth.Controls
            If TypeOf Ctrl Is CheckBox AndAlso DirectCast(Ctrl, CheckBox).Checked Then
                DaysOfWeekValue = DaysOfWeekValue + CInt(DirectCast(Ctrl, CheckBox).Tag.ToString)
            End If
        Next

If DaysOfMonthValue + DaysOfWeekValue = 0 AndAlso Me.CommandToRun.Text.Equals(String.Empty) Then
But I just realised that this allows them to select any number of checkboxes but leave the command line blank.

Any advice appreciated