error in alias please help

help with alias

[nasser bahaj]

hi guys

please help me in this problem

i have a subdomain on my main domain , i want to redirect it to main domain

for example :

http://download.example.com/index.php

redirect to

http://www.example.com/index.php

without change the address in address bar

i tried this

alias / /home/myuser/public_html

in .htaccess file and i uploaded it to (download) dir

but it give me "internal server error"

i cannot understand the problem

thanks for your time

[edited by: jdMorgan at 4:38 pm (utc) on Apr 8, 2010]
[edit reason] Please use example.com only. See Terms of Service and Charter. [/edit]

[g1smd]

I want to redirect it to main domain

without change the address in address bar

A redirect will always change the URL. A redirect tells the browser to make a new request for a different URL.

You'll need a rewrite if the URL isn't to change; however do be aware that serving the same content at multiple URLs will be an indexing and ranking disaster.

You should redirect non-canonical URL requests to the canonical form, and then that URL - and only that URL - should return the content.

[nasser bahaj]

thank you very much for your quick reply

but i cannot understand this point

You should redirect non-canonical URL requests to the canonical form, and then that URL - and only that URL - should return the content.

[g1smd]

Instead of the same content being available at A, B, C, D and E, make it so that only of those serves the content and all the others are redirected to that one.

[jdMorgan]

To clarify, this is a very bad idea: "without change the address in address bar" as doing so will create the duplicate-content problem that g1smd is warning you about, possibly ruining your search engine rankings.

Jim

[nasser bahaj]

g1smd
jdMorgan

thank you very much for your help

best regards