Hi

Struggling with the validation rules and using to fields to Validate.

Both conditions when true - field required.

Form breakdown

Control  A - Choice Drop down control (used for filtering a large list over 4000 entries)

Values are  0-9,A-D,E-H,I-M,N-Q,R-U,V-Z

Control B - Lookup control

if Control A choice is '0-9', this control is visible (working). It should also be invalid if '0-9' is selected AND isNullOrEmpty.

Separately the following rules work: IsNullOrEmpty({Self}) - control B required

Contains(Control A, "0-9") - Control B required

I have tried the following formulas on control B:

isNullOrEmpty({Self}) && contains(Control A, "0-9") - Does not make Control B required

and(isNullOrEmpty({Self}), contains(Control A, "0-9")) - Does not make Control B required

I know it must be something basic I have missed but I struggling at this one.

Thoughts anyone ?

Thanks

Rob