Validation and Input masks

[Santi]

Hi I am new in the forum and have basic knowledge of Access. My question is:
I want to validate a field with 3 letters and 4 numbers; e.g.: SAN2367

Any ideas?

[rommelgenlight]

what do you mean? you want to validate if a field value has first 3 letter characters and last four characters or you want to validate a field with 3 letters and 4 numbers if already exists?

if you want to validate if a field has first 3 letters characters and last four number characters then it will be better if you just use the input mask "LLL####" in this way, values will be input through this masking and you don't need to validate with any codes.

[Santi]

Thanks, I want to validate a field with 3 letters and 4 numbers that already exists.

[rommelgenlight]

you can use dlookup or select function.