JAVASCRIPT

javascript change input value

document.getElementById("ID").value = "Tamer Jarrar"; 

javascript change input value event

<input type="text" value="" onchange="updateInput(this.value)" />
  
<script>
function updateInput(ish){
    document.getElementById("fieldname").value = ish;
}
</script>

javascript set input value

<input type="text" id="example"> // Setup text field 
<script type="text/javascript"> 
  document.getElementById("example").setAttribute('value','My default value');
</script>

javascript input value change

function updateInput(ish){
    document.getElementById("fieldname").value = ish;
}