Display PCBTEXT entry “prompt” and get a string (maximum length “len”, valid characters “valid”, flags “flags”) from the user, assigning it to “var”

      valid length:     1-256  
      valid characters: any string  
      valid flags:      ECHODOTS  
                        FIELDLEN  
                        GUIDE  
                        UPCASE  
                        STACKED  
                        ERASELINE  
                        NEWLINE  
                        LFBEFORE  
                        LFAFTER  
                        WORDWRAP  
                        NOCLEAR  
                        HIGHASCII  
                        AUTO  
                        YESNO  

See also: DispText