Problem to receive character in PIC18

[nurul]

hii..

My PIC18 has problem to receive a character from PC. I'm using Visual Basic 6 in PC to give command to PIC to read current temperature. I'm also using zigbee to transmit and receive data between PC and PIC. The coding in VB6 is to send a character 'a' when button command is clicked. So my PIC18 should receive the character and execute the next line of instruction where to measure temperature. How to read the character in PIC and proceed the next line using soft_uart?
I've tried this coding but the PIC seems like not receive the character..
Soft_UART_Read(inputr);

if (inputr == 'a')
{
measure temperature
}