multiple semaphore problem..plz help.

[confusion]

i am attaching a code .plz tell me the flow of this code.i dont understand its working .. my doubt is 1)since task A is already pending on semaphore A,then after the OSTIMEDLY(100), there will be a context switch to task B .and in Task B, it requests to pend on semaphore b. so is it possible that the function under semaphore b which is an lcd display function will execute?? bcoz this resource that is lcd is already acquired by semaphore a. then will the function run??..plz reply asap

PROGRAM :-
#include "config.h"
#include "stdlib.h"
#include<LPC21xx.H>
#include<key.h>
#include<lcd.h>


OS_STK Task1Stack[100];
void Task1(void *pdata);

OS_STK Task2Stack[256];
void Task2(void *pdata);

static OS_EVENT *semaphorea;
static OS_EVENT *semaphoreb;


int  main (void)
{
   	keyinit();
	LCDInit();
	lcdcmd(0x80);
	LCDInit();
	
	OSInit();
	semaphorea = OSSemCreate(1);	 //counting semaphore ,1st semaphore
	semaphoreb = OSSemCreate(1);     //2nd semaphore
	if(semaphorea!=NULL)
	{
		DisplayLCD("Sema a create",13);
	}
	else
	{
		DisplayLCD("Sema a not create",17);
	}
		if(semaphoreb!=NULL)
	{
		DisplayLCD("Sema b create",13);
	}
	else
	{
		DisplayLCD("Sema b not create",17);
	}
	delay();
	clrscreen();
	delay();
	//DisplayLCD("Key:   LCD:");
	OSTaskCreate(Task1, (void *)0, &Task1Stack[99], 0);
   	OSTaskCreate(Task2, (void *)0, &Task2Stack[255], 1);

	OSStart();
	return 0;
}

	
void Task1 (void *data)
{

  int n, i;
  char err;
  data = data;     

  while(1)
  {
		
   OSSemPend(semaphorea, 1, &err);  
   
    clrscreen();
  DisplayLCD("task1:sem a taken",17);
   for(i=0;i<900000;i++);
  
   OSTimeDly(100);
   OSSemPend(semaphoreb, 1, &err); 

   	OSTimeDly(100);
  
   OSSemPost(semaphorea);
   OSSemPost(semaphoreb);           
   
   
  }
}


void Task2 (void *data)
{
 
  int n,i;
  char err;
  data = data;     

  while(1)
  {			
   
   OSSemPend(semaphoreb, 1, &err); 
   clrscreen();
  DisplayLCD("Task2:Sem b Taken",17);
   for(i=0;i<900000;i++); 
   
   OSTimeDly(100);
    OSSemPend(semaphorea, 1, &err);  
   
   OSTimeDly(100);
   
   OSSemPost(semaphoreb);  
   OSSemPost(semaphorea);           	
  }
}