problem in Generating random nmber using rand() function in embedded c

i modified the example random number generation program from keil help section.
keil example program
Code:

#include <stdlib.h>
#include <stdio.h> /* for printf */

void tst_rand (void) {
  int i;
  int r;

  for (i = 0; i < 10; i++) {
    printf ("I = %d, RAND = %d\n", i, rand ());
  }
}

my program was
Code:

 #include<reg51.h>
 #include <stdlib.h>
 sfr lcd_data_pin=0xA0;//p2 port
sbit rs=P1^0;
sbit rw=P1^1;
sbit e=P1^2;
void delay(unsigned int count)    //Function to provide delay
{
    int i,j;
    for(i=0;i<count;i++)
    for(j=0;j<1275;j++);
}
void lcd_cmd(unsigned char value)
{
        lcd_data_pin = value;
        rs=0;
        rw=0;
        e=1;
        delay(1);
        e=0;
        delay(1);
}
void lcd_data(unsigned char value)
{
        lcd_data_pin =value;
        rs=1;
        rw=0;
        e=1;
        delay(1);
        e=0;
        delay(1);
}
void lcd_init()
{
         lcd_cmd(0x38);
        lcd_cmd(0x0e);
        lcd_cmd(0x01);
        lcd_cmd(0x80);
}
void lcd_string(unsigned char *disp)     //LCD string function
{
        char x;
        for(x=0;disp[x]!=0;x++)
        {
                lcd_data(disp[x]);
        }

}

  void lcd_data_int(int time_val)               //  to send three digit number
{
        int int_amt;
    int_amt = time_val/1000;
        lcd_data(int_amt+48);
        time_val = time_val%1000;
        int_amt = time_val/100;
        lcd_data(int_amt+48);
        time_val = time_val%100;
        int_amt = time_val/10;
        lcd_data(int_amt+48);
        int_amt = time_val%10;
        lcd_data(int_amt+48);
}

void tst_rand (void) {
  unsigned int i;

  i= rand();
 lcd_cmd(0x80);
lcd_string("number: ");
delay(250);

lcd_cmd(0xc0);
 lcd_data_int(i);


}
void main()
{
lcd_init();
  while(1)
   {
          tst_rand ();
   }

}

when i compile this code it gives 3 warnings and when simulate in proteus it was blinking...no output

this is the 3 warnings from keil

Rebuild target 'Target 1'
compiling rand.c...
linking...
*** WARNING L7: MODULE NAME NOT UNIQUE
MODULE: G:\PROGRAM FILES\KEIL\C51\LIB\C51S.LIB (RAND)
*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL
SYMBOL: RAND
MODULE: rand.obj (RAND)
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
SYMBOL: RAND
MODULE: rand.obj (RAND)
ADDRESS: 0129H
Program Size: data=15.0 xdata=0 code=461
creating hex file from "rand"...
"rand" - 0 Error(s), 3 Warning(s).
So help me to solve this issue