function togglefix() {
	var fixcheckbox = document.getElementById("fix");
	if (fixcheckbox.checked) {
	  fixheader();
	} else {
	  unfixheader();
	}
}

function  fixheader() {
	var tableheader = document.getElementById("tableheader");
	var fakeheader = document.getElementById("fakeheader");

  tableheader.style.position = "fixed";
  tableheader.style.width = "874px";
  fakeheader.style.display = "block";  
}

function  unfixheader() {
	var tableheader = document.getElementById("tableheader");
	var fakeheader = document.getElementById("fakeheader");

  tableheader.style.position = "relative";
  tableheader.style.width = "auto";
  fakeheader.style.display = "none";  
}