You have to define the arguments server side.
Client side:
triggerServerEvent ( "onLogin", localPlayer, username_editbox, password_editbox )
Server side:
function login_seq ( username, password )
local username = mysql_query ( handler, "SELECT account_name FROM account_info WHERE account_name = ".. username .."" )
local password = mysql_query ( handler, "SELECT account_password FROM account_info WHERE account_password = ".. password .."" )
if ( username and password ) then
spawnPlayer ( client, 1687.7318115234, 1448.0688476563, 10.768267631531, -90, 0, 0 )
setCameraTarget ( client, client )
setElementDimension ( client, 0 )
end
end
addEvent ( "onLogin", true )
addEventHandler ( "onLogin", root, login_seq )
P.S: You also had a missing 'end' to close the 'if' statement.