how to allow characters, space and dot in regular expression?

Question

ValidationExpression=\"^[a-zA-Z ]+$\"

this is my current regular expression but it does not accept .(dot). I need to use it for names. like \"R

Answer 1

Validation for must contain a number, a character and a dot. Sometimes it must include a space.

For example:

version1.1.1-----valid
            version 1.1.1---valid
              v1.1.----------not valid(not end with dot)
             .v1.1--------not valid(not start with dot)
               v1----valid
               version 12.1.1--------valid

It must contain character and number dot and space are necessary if its dot not start with dot and not end with dot