dropdown not working in ie7 and ie8

If you have created dropdownlist and either its not visible or not visible onchange event of other dropdown
Then one of possible solution this is as follows:

Possible Cause :
if you use firebug and see html for dropdown you will notice that 'option' is not well formed in html for this dropdown.

One of Solution to Resolve this Problem:

If you have used something like this

for (i = 1; i <= day_length; i++)
{

doc.innerHTML += "<OPTION value=\"" + i + "\">" + i + "</OPTION>";
}
and adding items to dropdown (doc) dynamically with some values(eg: i in this case) replace this with

addOption(doc, i, i);

function addOption(selectbox,text,value )
{
var optn = document.createElement("OPTION");
optn.text = text;
optn.value = value;
selectbox.options.add(optn);
}

this add option adds all of those values which you want (eg: i ) and this will event work in ie 7 ,ie8.

It worked for me hope same would for you..

Cheers...