function checkWidth(){
  
 
  // to define a body-class
  if (self.innerHeight) // all except ie
 {
   x = self.innerWidth-20;
 }
 else if (document.documentElement && document.documentElement.clientHeight)
   // ie6 Strict Mode
 {
   x = document.documentElement.clientWidth;   
 }
 else if (document.body) // other ie
 {
   x = document.body.clientWidth;
 }
 //alert(x);
 if (x>=1024){
   className='wBig';
 } else if(x>=800){
   className='w1024';
 }else{
   className='w800';
 }
 document.body.className=document.body.className+' '+className;
}

// ÏÅÐÅÊËÞ×ÅÍÈÅ ÂÊËÀÄÎÊ
function tabChange() {
   var checkForm1 = document.getElementById('type1');
   var checkForm2 = document.getElementById('type2');
   if (checkForm1.checked) {
      document.getElementById('tab2').className='tab';
      document.getElementById('tab1').className='tab sel';
      document.getElementById('tab1content').style.display='block';
      document.getElementById('tab2content').style.display='none';
   } else {
      document.getElementById('tab1').className='tab';
      document.getElementById('tab2').className='tab sel';
      document.getElementById('tab1content').style.display='none';
      document.getElementById('tab2content').style.display='block';
   }
}
// ÂÛÁÎÐ ÏÅÐÅÏËÅÒÀ
function coverChange() {
   if (document.getElementById('chk_cover0').checked) {
      document.getElementById('params0').style.display='block';
      document.getElementById('params1').style.display='none';
      document.getElementById('params2').style.display='none';
      document.getElementById('params3').style.display='none';
      document.getElementById('covertab').style.display='none';
   }
   if (document.getElementById('chk_cover1').checked) {
      document.getElementById('params0').style.display='none';
      document.getElementById('params1').style.display='block';
      document.getElementById('params2').style.display='none';
      document.getElementById('params3').style.display='none';
      document.getElementById('covertab').style.display='block';
   }
   if (document.getElementById('chk_cover2').checked) {
      document.getElementById('params0').style.display='none';
      document.getElementById('params1').style.display='none';
      document.getElementById('params2').style.display='block';
      document.getElementById('params3').style.display='none';
      document.getElementById('covertab').style.display='none';
   }
   if (document.getElementById('chk_cover3').checked) {
      document.getElementById('params0').style.display='none';
      document.getElementById('params1').style.display='none';
      document.getElementById('params2').style.display='none';
      document.getElementById('params3').style.display='block';
      document.getElementById('covertab').style.display='none';
   }
}

// ÑÌÅÍÀ ÐÀÇÌÅÐÎÂ
function sizeChange() {
   selectForm = document.getElementById('selectw_size');
   if (selectForm.value == "A0") { w=841; h=1189; }
   if (selectForm.value == "A1") { w=594; h=841; }
   if (selectForm.value == "A2") { w=420; h=591; }
   if (selectForm.value == "A3") { w=297; h=420; }
   document.getElementById('size_w').value = w;
   document.getElementById('size_h').value = h;
}