I was update my old 6.31 version of GameStudio with last updates v6.51, and when i run my old code i get error message: syntax error and read only key_x

Here is example:

create(<bonusup.tga>,my.x,exp_display); //Syntax Error

IF (mouse_left == 1) { key_alt = 1; } //Read only key_alt

What i must change in these lines if i want get this code to work?

thanks