function box_odliczanie()
{
 aktualna_data=new Date();

 mr=aktualna_data.getMonth()+1;
 d=aktualna_data.getDate();
 h=aktualna_data.getHours();
 m=aktualna_data.getMinutes();
 s=aktualna_data.getSeconds();
 
 if ( mr<12 ) d1=30-d+31;
 else d1=31-d;

 h1=24-h-1;

 m1=60-m-1;

 if ( s==0 ) m1+=1;

 s1=60-s;

 if ( s1==60 ) s1=0;

 if ( m1<10 ) m1="0"+m1;

 if ( s1<10 ) s1="0"+s1;

 document.getElementById("dni").innerHTML=d1;

 document.getElementById("godziny").innerHTML=h1;

 document.getElementById("minuty").innerHTML=m1;

 document.getElementById("sekundy").innerHTML=s1;

 setTimeout("box_odliczanie()",1000);
}