help please

i want to do a project to detect the occurence of accidents and to auto dial a telephone number. Detection should be done using ultrasonics.i should use PIC16f877 and 8880 dtmf transceiver , kindly give me some idea or even the code and circuit diagram

A distance measuring appl : note is available at microchip site , couple it with dtmf tx

thank u but i need some more info ,pls

can u give additional information about how to recover the particular information from microchip(ie., app note of ultrasonic ranger )