跪求高手賜教C程序問(wèn)題？

void delay(unsigned int cnt)
{
        while(--cnt);
}

main()
{

        P0=0xff;
        while(1)
        {
                {if(!key1)
                       out1=0;
        out2=0;}問(wèn)題：我想在此加入1S延時(shí)，使之在亮1S后為1，就是關(guān)閉？
        
                {if(!key2)
                        out1=1;}
      
       
               
       
               

        }

}