CallFunc.BAS -- Test BASIC User-defined Function Statements                     
The next printed line should be from the Function.                              
                                                                                
This is written from the Function.                                              
The value of variable <xarg> is 5                                               
The value of variable <yarg$> is Hello                                          
The value of variable <tvar> is  17                                             
The value of variable <tvar> is reset to  99                                    
The Function should return  104                                                 
                                                                                
This is back at the main program.                                               
The value of variable <testvar> is now  17                                      
The returned value from the function is  104                                    
Did it work?                                                                    
