following is my code

#include <avr/io.h>
#include <util/delay.h>

#define Delay_ms(x) _delay_ms(x)
#define RS   1       //PC0
#define RW   1       //PC1
#define EN   2       //PC2


void lcd_cmnd(unsigned char);
void lcd_data(unsigned char dta);


int main()
{
    DDRC=0xff;
    DDRD=0xff;
    lcd_cmnd(0x38);          //sets 8-bit interacing
    Delay_ms(1);


    lcd_cmnd(0x0e);           //display on
    Delay_ms(1);
    lcd_cmnd(0x08);           //display off
    Delay_ms(1);
    lcd_cmnd(0x01);        //clears screen
    Delay_ms(1);



    lcd_cmnd(0b00000000);
    lcd_cmnd(0x06); //Entry Mode, Increment cursor position, No display shift

    lcd_data('N');
    Delay_ms(250);

    lcd_data('a');
    Delay_ms(25);
    lcd_data('s');
    Delay_ms(25);
    lcd_data('i');
    Delay_ms(25);
    lcd_data('r');
    Delay_ms(25);
return 0;
}
void lcd_cmnd(unsigned char cmd)
{
    PORTD=cmd;
    PORTC=(0<<RS);                //command mode   PC0=RS(low)
    PORTC|=(0<<RW);                // read mode  PC1=RW
    PORTC=(1<<EN);                 // enable high   PC2=EN
    Delay_ms(1);
    PORTC=(0<<EN);                 //enable low
    Delay_ms(50);
}

void lcd_data(unsigned char dta)
{

    PORTC|=(0<<RW);              //PC1=RW (low)
    PORTC|=(1<<0);               //DATA mode   PC0=RS
    PORTD=dta;
    PORTC=(1<<EN);                //enable high   PC2=EN


    Delay_ms(1);
    PORTC=(0<<EN);                //enable low
    Delay_ms(50);
}

It executes well, the simulation in proteus runs well but the characters are not shown. hte cursor just blinks and nothing is displayed. I don't know why?

Following is another code which runs good and every thing is displayed on lcd as "Hello World!"

#include <avr/io.h>
#include <stdlib.h>
#include <util/delay.h>
#include <stdio.h>

//Define functions
//==========================================================
void io_init(void);                         //Initializes IO
void send_nibble(unsigned char __rs, unsigned char __data);

//==========================================================

int main (void)
{
    io_init();

   _delay_ms(15);
   send_nibble(0,0b0010);   //Set to 4 bit operation (note: 1 nibble operation)
   _delay_ms(5);

   send_nibble(0,0b0010);   //Function set, 4 bit
   send_nibble(0,0x08);     //display off, cursor off

   send_nibble(0,0b0000);
   send_nibble(0,0b1111);   //Display ON, Cursor On, Cursor Blinking

   send_nibble(0,0b0000);
   send_nibble(0,0b0001);   //Clear Display

   send_nibble(0,0b0000);
   send_nibble(0,0x06); //Entry Mode, Increment cursor position, No display shift

   send_nibble(1,0b0100);  //H
   send_nibble(1,0b1000);

   send_nibble(1,0b0110);  //e
   send_nibble(1,0b0101);

   send_nibble(1,0b0110);  //l
   send_nibble(1,0b1100);

   send_nibble(1,0b0110);  //l
   send_nibble(1,0b1100);

   send_nibble(1,0b0110);  //o
   send_nibble(1,0b1111);

   send_nibble(1,0b0010);  //Space
   send_nibble(1,0b0000);

   send_nibble(1,0b0101);  //w
   send_nibble(1,0b0111);

   send_nibble(1,0b0110);  //o
   send_nibble(1,0b1111);

   send_nibble(1,0b0111);  //r
   send_nibble(1,0b0010);

   send_nibble(1,0b0110);  //l
   send_nibble(1,0b1100);

   send_nibble(1,0b0110);  //d
   send_nibble(1,0b0100);

    return(0);
}

void io_init (void)
{
    /*
    PC 7: N/A
    PC 6: Reset
    PC 5: Enable
    PC 4: Register Select
    PC 3: Data 7
    PC 2: Data 6
    PC 1: Data 5
    PC 0: Data 4
    */

    DDRC = 0b00111111;  //63
}

void send_nibble(unsigned char __rs, unsigned char __data)
{
   PORTC = (__rs<<4) | __data | 0b00100000;      // Set RS &amp; Data. Set EN=High
   _delay_ms(1);
   PORTC = (__rs<<4) | __data;                   // Set RS &amp; Data. Set EN=Low
   _delay_ms(1);
}

I tried to proceed in same order but in vain. and i am stuck in learning the lcd programming from last 10 days. Any healthy and effective help is appreciated in advance!