Error in uploading plugins help please

[webfairy]

Hi, i up loaded and installed and did 2 plugins on one of my domains.
Now i have uploaded and installed the basic Coppermine to my other Domain and everything seems to be ok but the Plugin function.
I try to upload a plugin (the same 2 I did on the other domain:
1. cpg1.4.3_plugin_CPGMassImport_2.0.zip
2. usergal_alphatabs.zip

and this is the message I get for them both.   

Critical error
There was an error copying the package to the plugins folder.

Could some one tell me exactly what is wrong and what I have to do to fix it.  Thanks

[Nibbler]

Ensure the plugins directory on your server is writable.

[webfairy]

Thanks Nibbler,  i just thought of that and changed it from 755 to 777...and it worked.  Duh!!!!  my brain is not working this am.  Thanks again.

Ensure the plugins directory on your server is writable.