Create a boolean variable and set it to false when the player is spawned. When the player opens the menu set it to true. Only allow the player to open the menu if the boolean is false.
PHP Code:
new bool: g_bUsedMenu[ 33 ];
//Spawn
g_bUsedMenu[ id ] = false;
//In menu function
if ( g_bUsedMenu[ id ] )
return
g_bUsedMenu[ id ] = true;
//menu code