for loop stopping

[#1]

I'm stumped at the moment on an issue with a FOR loop.  (using JMP16)  

// open a window
mywindow = New Window(" xyz ", .....etc.);

// create journal
myjrn = mywindow << journal window; 

For( i = 1, i <= 100, i++,  

// do a lot of lines of lines requiring about 5' run time.
	// periodically journal objects.

	Close All( data tables, no save )
);  // end to for loop

// SAVE the journal:
myjrn << save journal( "my.jrn" );

The loop stops after an iteration. 

(I can restart the loop after the for (i=1, i<=100, i++,   stops and doesn't proceed to i=2. 

for (i=2,i<=100, i++,  stops and doesn't proceed to i=3.

for (i=3,i<=100, i++, stops and doesn't process to i=4. 

Welcoming thoughts on what is causing this? resolution?

Thanks,

John

[#2]

Does each code in each iteration depend on the data tables that you are closing within the For() function?

[#3]

Without seeing all the code it's difficult to diagnose.

First check the log window for any errors.

If there are none, then I'd start with looking at the value of i after the For() loop. I suspect you'll find it's greater than 100. Then you need to see where it is getting changed inadvertently. This can occasionally happen with name collisions with columns in a data table. If you just can't figure out where that could be happening, try changing the i to something else and see if it starts working. That will confirm the name collision.

[#4]

Is it possible that somewhere in your Fro() loop, that you are setting the variable "i" to a large value?

[#5]

Do you have other parts of code using "i" as a variable?  Could the variable be getting reassigned (e.g. if you are using user-defined functions)?