Check for a "rand" or "random" function in the list, but if there isn't any "rand" or "random" function in  Ctrl+I function list, it's probably impossible to do it in jaws script.

Hello,

Lets look at the issues one by one.
First compile error I get, "unknown variable mb_ok".

This is because the MB_Ok item is part of the FS standard libraries. You need to include them, usually at the top of your script file.

include "hjconst.jsh"
include "hjglobal.jsh"

Next error: " Function ExMessageBox requires 3 parameters not 4".

This is because you've got a comma in what should be the first parameter, you need to have the value that you are looking for, quote, pplus. Instead of quote then a comma.

next error: " Parameter 1 to Function ExMessageBox  should be of type string not int"

This is because you are trying to use a say function within a message box.  The say functions output text to the synthesizer.  TO display a number inside a message box you need to use the IntToString function in place of SayInteger.

With the above changes, compilation succeeds.  running the script, I get: "FYI! Dialog
The value that you are looking for is25
OKButton"

My complete code is below:

include "hjconst.jsh"
include "hjglobal.jsh"
Script Test ()
VAR
int X,
int Y,
int Z
X=Y+Z
Y=155*120
Z=25
ExMessageBox ("The value that you are looking for is"+ intToString(Z), "FYI!", MB_OK)
EndScript

that's perfect.

One thing to note is that x will -=0 in this script, because when you wrote X=Y+Z, Y and Z were both 0.  you only changed their values after you assigned X.

If you need any further help, please ask; I am happy to oblige.

No, not quite correct.

In your first script, you wrote:

X=Y+Z
Y=155*120
Z=25

If you output these, Z=25, Y=18600, and X=0.

X=0 because, when you wrote X=Y+Z, Y and Z both=0.

if you move the lines, so you had:

Y=155*120
Z=25
X=Y+Z

X now =465000.
y, 18600, multiplied by (*) Z, 25).

I hope this helps explain.

Nicely explained, thanks again. Now I feel like I should step into more complex scripting methods, like decision making, function calling etc.