Interacting with user over serial..

I am having problems reading in from the usb/serial rs232 to the arduino. The function is being ignored for some reason. I have tried many different ways, but nothing is helping.
In the following sketch, the function set_time() is only printing the strings but is not waiting for the user inputs, am I doing something wrong?

#include <Wire.h>

void intro()
   Serial.println("What would you like to do:");
   Serial.println("\t1) Set the time and date");
   Serial.println("\t2) Display the time in a loop until a key is hit (update every sec).");
   Serial.println("Yor selection: ");

void setup()
  Serial.println("Hello Welcome to the clock, designed to test how I2C works with the DS1307\n");

void set_time()
 int  yr[2], mn[2], dt[2], dy, hr[2], mi[2], sec[2], day[2];

 Serial.println("Set time.");
//  if (Serial.available() > 0) {
 Serial.print("Enter the year (00-99): ");
 yr[0] =;
 yr[1] =;
 Serial.print("Enter the month (01-12): ");
 mn[0] =;
 mn[1] =;
 Serial.print("Enter the date (01-31): ");
 dt[0] =;
 dt[1] =;
 Serial.print("Enter the day (1-7): ");
 dy =;
 Serial.print("Enter the hour (01-23): ");
 hr[0] =;
 hr[1] =;
// hr = hr & 0x3f;      /* force clock to 24 hour mode */
 Serial.print("Enter the minute (00-59): ");
 mi[0] =;
 mi[1] =;
 Serial.print("Enter the second (00-59): ");
 sec[0] =;
 sec[1] =;
//  }

void display_time()
 Serial.println("Display time."); 

void loop()
  int m=0;
  if (Serial.available() > 0) {
   m =;
    if (m==49)
    else if (m==50) 
     Serial.print("Wrong selection: ");

Thanks for your help. will return if there is nothing in the input buffer; you need to check and see if something is available, then read it. For example

    while (!Serial.available())
    c =;

This code loops until something is available to read.

I think you can also check the return status to find out if the read was succesful, but check the documentation to be sure.