Hello, I am pretty new to JavaScript, but I am working on a project. Currently I have to find a way to determ if a postalcode is an correct postal code. (A dutch postal code) For that I will have to confirm if two correct letters are entered in the form.I think my explanation is really unclear, so I will try to make it more clear for everyone. The postal codes in The Netherlands look like this: 1234 AB. In one place, e.g. Amsterdam, they use the letters "AA, AB, AC, AD, AG, AH, AJ" etc. The script has to look for one of those letters with the correct combination (AA, AB, AC, AD, etc). If I ent