Level couldn't be loaded because its not added to build settings, but it is?

Hey I am trying to make my menus work for when I die a game over screen appears and the player has the option to either restart or go to the main menu, however when I try to link the scenes together by putting Application.LoadLevel("1"); it doesnt work, it works when I put the name of the scene, however I am having a problem when I click restart, it goes to the game then goes back to the restart screen, if I press main menu from the restart screen then press play, it goes back to the restart screen even tho its linked to the game scene :S, which is really fustrating, I donno what I am doing wrong, thanks for your time in reading this I hope someone can help.

Application.LoadLevel has 2 forms; one takes an integer argument, which is the index of the level in the list, and the other form takes a string which is the level name. If you are passing 1 as "1", it will be looking for a level named "1", not the level at position 1.

Is "1" the name of your scene? If not, you load scenes based on build order by using the actual integer, ie

Application.LoadLevel(1);

provided the scene you're trying to load is labeled as number one in the build settings.