9. A computer-readable storage medium containing computer-executable instructions which when executed by a computer perform the steps for checking a sequence of input characters, the steps comprising: determining whether a sequence checking feature operatively associated with a state transition table, containing allowable sequences of characters based on the rules of a selected language, is enabled, the sequence checking feature being set to operate by a registry entry setting set in the computer's operating system's registry, the registry entry setting being set in the computer's operating system's registry for each language requiring the sequence checking feature; upon determining that the sequence checking feature is enabled: receiving a first character of the sequence of input characters; receiving a second character of the sequence of input characters; determining whether the sequence of characters belongs to a set of characters comprising a selected language by determining that a sequential order of reception of the first character relative to reception of the second character is consistent with at least one valid sequence of characters, said determining that the sequential order of reception of the first character relative to the reception of the second character is consistent with the at least one valid input of characters comprises: assigning a first state to the first character according to rules associated with the selected language, assigning a second state to the second character according to the rules, and determining that the state transition table includes a state transition from the first state to the second state, the state transition from the first state to the second state indicating that the sequential order of reception of the first character relative to reception of the second character is consistent with the at least one valid sequence of characters based on the rules of the selected language, said determining that the state transition table includes the state transition from the first state to the second state comprises determining that the state transition table includes a cell corresponding to a cross-reference of the first character and the second character, the cell not being blank and not including only type and replacement actions; when the first character and the second character form the at least one valid sequence of characters according to rules associated with forming a complex character, displaying the complex character formed by the first character and the second character prior to accepting additional characters for display; when the first character and the second character do not form the at least one valid sequence of characters according to the rules associated with forming the complex character: displaying the first character, prohibiting the display of the second character, and requiring receipt of a third character as an alternate character.
14. The computer-readable storage medium of claim 9 , wherein the rules comprise at least one rule for creating complex characters according to the selected language.