Running su scripts from bash scripts

I want to execute these commands in a single script:

cd Pictures/2005
mkisofs -r -o tmp/Pictures2005.iso .
su
cdrecord -v -data dev=0,0,0 tmp/Pictures2005.iso .

The problem is that after it gets to su it never continues further with 
the script. I know there is a way to do it in bash, but I forgot, and the
quick look at the reference material did not lead me to any example of 
this kind. In short, I want to execute a set of super-user commands from 
within a script. In the simples case, it's ok if the user executing the 
script is asked to enter the root password. In the best case he'll not 
have to. Any example of that would be appreciated.

Andrei

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Dr. Andrei Smirnov,  West Virginia University
Dept. of Mechanical and Aerospace Engineering
Morgantown WV, 26506-6106
Tel:+1(304)293 3111 x2345, fax:+1(304)2936689
Email: [email protected]
http://smirnov.mae.wvu.edu     1024D/5CEDD3E2
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