function schema() {
  window.open('../datash/pic/at89c2051/at89c2051_2.gif','schema','width=700,height=600,position=0,resizable=yes,scrollbars=yes');
  }

function mod1() {
  window.open('../datash/pic/at89c2051/mod1.gif','mod1','width=400,height=100,position=0');
  }