It would be a good idea to get in the habit of indenting. When/if you get to the point were you have long scripts, it will help you alot.
function ServerCmdadmincheck(%client,%z)
{
if(%client.issuperadmin || %client.isadmin)
{
messageclient(%client,"","you are a admin");
}else{
messageclient(%client,"","Sorry, you are not an admin.");
}
}