Interrupt on Rising/Falling edge with a PIC32Mx (ffb.boy.30)

Hi again,Back again with my PIC32MX130F128L. Now I need to read 3 RC receiver signal.It is a PWM with a period of 20ms and the delay between the falling and rising edge goes from 1ms to 2ms.I would like to read it properly so I thought about the Input cap..