select Onchange js code example
Example 1: onchange on select tag
<select id="comboA" onchange="getComboA(this)">
<option value="">Select combo</option>
<option value="Value1">Text1</option>
<option value="Value2">Text2</option>
<option value="Value3">Text3</option>
</select>
Example 2: js html textbox on change
<input type="text" onkeydown="keydownFunction()"
onkeyup="keyupFunction()" onchange="changeFunction()">
Example 3: javascript input value change
function updateInput(ish){
document.getElementById("fieldname").value = ish;
}