how to keep innerHTML value unchanged?

[jsutariya]

how to append the value of innerHTML in javascript without changing the first inserted values?
I have generated a combobox in my page and creating new combobox using ajax.
but when I try to add new combobox the selected value of previous combobox is get reset.
How can I avoid it.

batch_field=document.getElementById('stock_add').innerHTML;
		batch_field = batch_field.concat(xmlhttp3.responseText);
		document.getElementById('stock_add').innerHTML = batch_field;

I am using upper code to append the first innerHTML value in the next created innerHTML.

[Dormilich]

you can use the Shorthand Assignment Operators. in your case: +=.

[jsutariya]

still not working..
will you please provide your own example or code??

[Dormilich]

something as simple as that

document.getElementById('stock_add').innerHTML += xmlhttp3.responseText;