function open_window(link){
  window.open(link);
}

function showElem(id)
{
  elem=document.getElementById(id);
  //alert('show '+id);
  elem.style.display='';
}
function hideElem(id)
{
  elem=document.getElementById(id);
  //alert('hide '+id);
  elem.style.display='none';
}

function enableElem(elem)
{
  elem.disabled=false;
}
function disableElem(elem)
{
  elem.disabled=true;
}

// Function change value of form element
function changeValue(elem,newVal)
{
  elem.value=newVal;
}

// Function changes content of HTML tag
function changeHTML(id,newVal)
{
  var elem = document.getElementById(id);
  //alert(elem);
  elem.innerHTML=newVal;
}