function changePrumer(prumer) {
      document.getElementsByName('prumer-pevny')[0].disabled=!(prumer.selectedIndex==1);
      document.getElementsByName('prumer-plyn')[0].disabled=!(prumer.selectedIndex==2);
      }

function changePrumerSopouch(prumer) {
      document.getElementsByName('prumer-pevny')[0].disabled=!(prumer.selectedIndex==1);
      document.getElementsByName('prumer-plyn')[0].disabled=!(prumer.selectedIndex==2);
      document.getElementsByName('sopouch')[0].disabled=!(prumer.selectedIndex==1);
      }

function changePrumerSopouch2(prumer) {
      document.getElementsByName('prumer-pevny2')[0].disabled=!(prumer.selectedIndex==1);
      document.getElementsByName('prumer-plyn2')[0].disabled=!(prumer.selectedIndex==2);
      document.getElementsByName('sopouch2')[0].disabled=!(prumer.selectedIndex==1);
      }

function changePrumerSopouch3(prumer) {
      document.getElementsByName('prumer-pevny3')[0].disabled=!(prumer.selectedIndex==1);
      document.getElementsByName('prumer-plyn3')[0].disabled=!(prumer.selectedIndex==2);
      document.getElementsByName('sopouch3')[0].disabled=!(prumer.selectedIndex==1);
      }

function changeStriska(striska) {
      document.getElementsByName('striska-typ')[0].disabled=!(striska.selectedIndex==1);
      }