public doesn't work

[Jay]

Don't be too hasty to assume

Code:

set_mysql_loggedin_level(prname, level)
{
       new giveplayerid[MAX_PLAYER_NAME];
    new prname[MAX_PLAYER_NAME];
    GetPlayerName(giveplayerid,prname,sizeof(prname));
    format(strlogin, sizeof(strlogin), "UPDATE users SET loggedin='%d' WHERE name = '%s'", level,prname);
    samp_mysql_query(strlogin);
    samp_mysql_store_result();
}

Look at the variable declarations.
Your two variables are arrays.
The error "argument type mismatch" means that a function is not being passed the correct type of variable.
The variable "giveplayerid" should be an integer, not an array. The function GetPlayerName() will need to use an integer variable to check whose player's name to get.

Oh, by the way, don't use the script showroom for help threads. Those should go in the scripting section.

EDIT: Sorry, mis-read. I thought you was looking at the variable for actually storing the name in, not the variable for the players id!