JavaScript Reference/Javascript Properties/selectedIndex
"selectedIndex" Example
<html>
<body>
<script>
function function1(colors) {
var col = (colors.options[colors.selectedIndex].value);
if (col) {
document.bgColor = col;
}
alert("SelectedIndex value = "+col);
}
</script>
<form method="post" action="">
<select name="colors" onChange="function1(this);">
<option value="white" selected>White</option>
<option value="cyan">Cyan</option>
<option value="ivory">Ivory</option>
<option id="myO" value="blue">Blue</option>
<option value="red">Red</option>
<option value="lightblue">Lightblue</option>
<option value="beige">Beige</option>
</select>
</form>
"selectedIndex" is applied to
+----------------+--------------------------------------------------------------+
| Applied_To |<select> |
+----------------+--------------------------------------------------------------+
"selectedIndex" Syntax and Note
Note:
Read and write property.
The index of the selected <option> element.
Syntax:
document.getElementById("selectID").selectedIndex = value
document.all.selectID.selectedIndex = value // IE only