Replacing a pattern in one file by reading a string from another file

Hi,

I have 2 files, I am trying to replace a pattern in file2 with a string 
from file1, am not able to make headway, any suggestions would be 
helpful

File1 contents: [File1 has just this one string and nothing else]
11212005

File2 Contents:
BeginDate=$crtdate

In file2 $crtdate occurs multiple times and I am trying to use a SED 
script to replace the $crtdate in file2 with the "11212005" from file1.

Thx in advance for the help
Alk





------------------------ Yahoo! Groups Sponsor --------------------~--> 
Most low income households are not online. Help bridge the digital divide today!
http://us.click.yahoo.com/I258zB/QnQLAA/TtwFAA/dkFolB/TM
--------------------------------------------------------------------~-> 

-- 
 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/sed-users/

<*> To unsubscribe from this group, send an email to:
    sed-users-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/