Check if the field is a alphanumeric

Hi Iam trying to check my field city is a alphanumeric field or not.is it the correct way or is there any alternate method to do it.Its a client based application.

if uidoc.city like “[a-z,A-Z,0-9]” then

messagebox “some message”

Subject: You can do it with @forumla and a input validation formulaalphanumeric

Take a look in designer help at @matches and @success and @failure.

Subject: RE: You can do it with @forumla and a input validation formulaalphanumeric

You can also use the lotusscript Like operator