Accessing web.config key using javascript

I was using this way to get web.config key value in javascript:

http://praveensunsetpoint.wordpress.com/2008/04/05/read-configuration-settings-of-webconfig-using-javascript/

but i got this error:

Too many characters in character literal

because my string was very long. So I used this way instead:

http://forums.asp.net/p/1102442/1678722.aspx

Another way:

http://www.dotnetspider.com/forum/ViewForum.aspx?ForumId=132330