A question about the CHOOSE statement

cctvgun

There are 2 values: inventory quantity value (num) and out-of-stock quantity value (outnum). Different operations are performed according to the difference between the two data. The statement is as follows:
a = num-outnum

choose case a
case 0
             // perform all out of stock and delete entries in the inventory table
        case num
            // Prompt for data input greater than 0
        case> 0
            // Exit the warehouse normally, and update the entries in the inventory table
        case <0
           // Prompt input data cannot be greater than total inventory
end choose

This statement always prompts a syntax error during execution, please advise.

unkmass

a=num-outnum

choose case a
case 0
// Carry out all the warehouses and delete the entries in the inventory table
case num //It seems that only constants can be used
// Prompt input data must be greater than 0
case is> 0
// Normally leave the warehouse and update the entries in the inventory table
case is <0
// Prompt the input data can not be greater than the total inventory
end choose

unkmass

case num //It seems that only constants can be used
// Prompt input data must be greater than 0
------------- You can try this line and forget it.

cctvgun

Thanks, according to your post has been done

cctvgun

May use variables, I just tried

cloud5219

case is> 0
//
No, you can judge in front and then give straight a