@Kwon san 

You can use the code linked by Sarra below. It solves with the Finite Difference Method. 

@Will 

As an old-time latex user, I think this is the best feature in 9.5.  To include a latex code, simply enclose in \(  \). Sweet.

@sarra 

Thanks much for sharing the code. It helps a lot.

@Carl Love 

Thanks for the correction, Carl. My Maple code is right, though. I tend to think now that it is somewhat naive for me to find the C's as I did. It seems that the right approach is as explained by Prof. Lopez for solving Sturm-Liouville problem here http://www.maplesoft.com/applications/view.aspx?SID=4971.

But it's not too obvious to extend it to my problem.

@mehdi jafari 

Thanks Mehdi. It was the first thing I tried, but like Carl said, numeric option is not applicable to elliptic equations. It took me quite a while to realize this -- the documentation is not too obvious to me.

@jzivku 

Thanks much, Jonny.  The webinar helps--didn't check it before since I thought it was meant for experienced users.

I'm in a constant communication with the Maple reps in our region. Definitely I can get their help. Just to see here what I can benefit as a newbie from other Maple TA instructors.

Best,

Razi