GM_setValue — set script-specific configuration value
function GM_setValue(key, value
GM_setValue stores a script-specific configuration value. The
key argument is a string of no fixed format. The
value argument can be a string, boolean, or integer. Both arguments are required.
Greasemonkey configuration values are similar to browser cookies, but there are important differences. Both are stored on the local machine, but while cookies are domain-specific and can only be accessed from their originating domain, Greasemonkey configuration values are script-specific and can only be accessed by the user script that created them (regardless of the address the user script is currently running on). And unlike cookies, configuration values are never transmitted to remote servers.
GM_getValue was introduced in Greasemonkey 0.3.