Calculate a random numeric value 
     
    
     
     Calculates a random character string 
     
    
     
     Determines the position of last occurrence of a substring within a 
     
    
     
     Establishes the up arrow key and down arrow key as exit keys for READ. 
     
    
     
     Reads/sets insertion mode for GET input fields or MemoEdit(). 
     
    
     
     This function is not supported by Xbase++.