Matrix keypad interfacing pic18f4550

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unsigned short kp, cnt, oldstate = 0;
char txt[6];
// Keypad module connections
char keypadPort at PORTC;
// End Keypad module connections
// LCD module connections
sbit LCD_RS at RB1_bit;
sbit LCD_EN at RB0_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;
sbit LCD_RS_Direction at TRISB1_bit;
sbit LCD_EN_Direction at TRISB0_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;
// End LCD module connections
void main() 
{
  cnt = 0; // Reset counter
  Keypad_Init(); // Initialize Keypad
  Lcd_Init(); // Initialize Lcd
  Lcd_Cmd(_LCD_CLEAR); // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off
  Lcd_Out(1, 1, "1");
  Lcd_Out(1, 1, "Key :"); // Write message text on Lcd
  Lcd_Out(2, 1, "Times:");
  do 
  {
    kp = 0; // Reset key code variable
    // Wait for key to be pressed and released
    do
      //kp = Keypad_Key_Press(); // Store key code in kp variable
      kp = Keypad_Key_Click(); // Store key code in kp variable
    while (!kp);
    // Prepare value for output, transform key to it's ASCII value
    switch (kp) 
    {
      case 1: kp = 49; break; // 1
      case 2: kp = 50; break; // 2
      case 3: kp = 51; break; // 3
      //case 4: kp = 65; break; // A commented since 4th column is absent for 4*3 keypad
      case 5: kp = 52; break; // 4
      case 6: kp = 53; break; // 5
      case 7: kp = 54; break; // 6
      //case 8: kp = 66; break; // B commented since 4th column is absent for 4*3 keypad
      case 9: kp = 55; break; // 7
      case 10: kp = 56; break; // 8
      case 11: kp = 57; break; // 9
      //case 12: kp = 67; break; // C commented since 4th column is absent for 4*3 keypad
      case 13: kp = 42; break; // *
      case 14: kp = 48; break; // 0
      case 15: kp = 35; break; // #
      //case 16: kp = 68; break; // D
    }
    if (kp != oldstate) 
    { // Pressed key differs from previous
      cnt = 1;
      oldstate = kp;
    }
    else 
    { // Pressed key is same as previous
      cnt++;
    }
    Lcd_Chr(1, 10, kp); // Print key ASCII value on Lcd
    if (cnt == 255) 
    { // If counter varialble overflow
      cnt = 0;
      Lcd_Out(2, 10, " ");
    }
 
    WordToStr(cnt, txt); // Transform counter value to string
    Lcd_Out(2, 10, txt); // Display counter value on Lcd
 } while (1);
}

Code C - [expand]
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void interrupt low_priority check_isr();
void RBIF_ISR();
 
void interrupt low_priority check_isr()        //Low Priority Interrupt
{
    if(INTCONbits.RBIF == 1)                //Check Which Casues this interrupt
    {
        RBIF_ISR();        //Call PORTB Change Interrupt Function
    }
}
 
 
unsigned char keypad[4][3] = {'1','2','3','4','5','6','7','8','9','C','0','='};
 
void main()
{
    
    TRISC = 0x10;
    TRISD = 0x00;
    lcd_init();
    __delay_ms(10);
    lcd_cmd(0x83);
    lcd_string("PIC18F4550");
    lcd_second_line();
    lcd_string("KeyPad Interface");
    __delay_ms(100);
    INTCON2bits.RBPU = 0;    //Enable Pull-Up Resistors
    TRISB = 0xF0;            //Upper pins as Input Pins and Lower Pins as Output Pin
    PORTB = 0xF0;
    
    while(PORTB != 0xF0);    //Wait Until Key Not Pressed
 
    INTCONbits.RBIE = 1;     //Enable PORT-B Change Interrupt
    INTCONbits.GIE = 1;      //Enable Global Interrupt
    lcd_cmd(0x01);
    while(1)
    {
        lcd_first_line();
        lcd_string("Key Pressed:-");
        __delay_ms(10);
    }
}
 
void RBIF_ISR()
{
    unsigned char temp,ROW = 4,COL = 0;
    unsigned char count = 0;
    temp = PORTB;        
    temp = temp ^ 0xF0;   //0b1111 0000
    if(temp == 0x00)      //If False Alram due to Noise then go Back
    {
        return;
    }
        
    while((temp=(temp<<1)) != 0)    //Find the Column
    { 
        COL++;
    }
    
    PORTB = 0xFE;    //Ground First Row //0b1111 1110
    if(PORTB != 0xFE)
    {
        ROW = 0;    //Row Selected
    }
    else
    {
        PORTB = 0xFD;    //Ground Seconmd Row //0b1111 1101
        if(PORTB != 0xFD)
        {
            ROW = 1;
        }
        else
        {
            PORTB = 0xFB;    //Ground Third Row //0b1111 1011
            if(PORTB != 0xFB)
            {
                ROW = 2;
            }
            else
            {
                PORTB = 0xF7;    //Ground 4th Row //0b1111 0111
                if(PORTB != 0xF7)
                {
                    ROW = 3;
                }
            }
        }
    }
    
    if(ROW < 4)
    {
        lcd_second_line();
        __delay_ms(10);
        lcd_dat(keypad[ROW][COL]);
        __delay_ms(10);
        lcd_first_line();
    }
    while(PORTB != 0xF0)
        PORTB = 0xF0;
        INTCONbits.RBIF = 0;
    
        
}