for (i=0;i<ds_grid_height(global.inventory);i+=1) {
  if (ds_grid_get(global.inventory,0,i)==0) {
    ds_grid_set(global.inventory,0,i,thisitemname);
    ds_grid_set(global.inventory,1,i,thisitemvalue);
    ds_grid_set(global.inventory,2,i,thisitemdescription);
    show_message("Setting the inventory value!");
    break;
  } else {
    show_message("Hmmm... Not equal to 0?");
  }
}
instance_destroy();