1. Increase option:
function addoption (pa0, pa1, pa2) // select control, the text display option, the option value value
{
var option = document.createElement("option");
option.appendChild(document.createTextNode(pa1));
option.setAttribute("value",pa2);
pa0.appendChild(option);
}
2. Get the selected option:
var obj = document.getElementByIdx_x(”testSelect”); //定位id
var index = obj.selectedIndex; // Select Index
var text = obj.options [index] .text; // selected text
var value = obj.options [index] .value; // selected value
3. Delete the selected option
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex;
obj.options.remove(index);
4. Empty select
mySelect.options.length=0;
Reproduced in: https: //my.oschina.net/secyaher/blog/274424