dictionary object
This method will check to see if a particular key exists in the dictionary.
bool exists(string key)
Parameters:
key
The key to look for.
Return value:
true if the key was found, false if it was not or if an error occured.
Remarks:
None.
Example:

    dictionary game_board; // Declare our dictionary.

    void main()
    {
    int value; // Declare a variable for retrieving values from a dictionary.
    // Set our values.
    game_board.set("1", 2); // Sets the value 2 to a key called 1.
    game_board.set("2", 4); // Sets the value 4 to a key called 2.
    if(game_board.exists("1"))
    {
    game_board.get("1", value); // Retrieve value for 1.
    alert("Dictionary example", "Key 1 contains value "+value);
    }
    else
    {
    alert("Error", "Key 1 does not exist in the dictionary.");
    }
    game_board.delete_all(); // Delete all the values.
    }