I am trying to make a simple toggle button in javascript

Both of your if statements are getting executed one after each other, as you change the value and then immediately read it again and change it back:

function toggle(button)
{
  if(document.getElementById("1").value=="OFF"){
   document.getElementById("1").value="ON";}

  else if(document.getElementById("1").value=="ON"){
   document.getElementById("1").value="OFF";}
}

Adding the else in there should stop this happening.