Easy Javascript question (getting dropdown list values)

[yarbrough40]

I'm a vb.net user mostly... can anyone tell me why I'm getting a runtime error 'permission denied' when running this? trying to get values from a dropdownlist.

 
function getvalues()
{
var dl = document.getElementById("DropDownList11");
var item1;

item1 = dl.options[0].value;
document.write(item1 + "<br>");

item1 = dl.options[1].value;      //error occurrs here
document.write(item1 + "<br>");
}

[Dormilich]

I think that happens when you try to use document.write( ) on an already loaded document. document.write( ) is not suited to modify a HTML page.

[yarbrough40]

thanks Dormilich, however that's not the answer. I can tell because this simple code executes without error...

function getvalues()
{
var string = "hello" + "<br>";
document.write(string); 

string = "world";
document.write(string); 
}

in my first example I show exactly where the error occurs and it's at the second time I use 'document.getEl ementById'... is there perhaps some kind of fundamental Java violation when attempting to get values from an object more than once?

[Dormilich]

in my first example I show exactly where the error occurs and it's at the second time I use 'document.getEl ementById'...

sometimes the line that throws an error is not the line that causes it…

anyway, I can’t see you using getElementById( ) twice.

if you can provide a link, I’ll have my FireBug peek at it.

[yarbrough40]

I figured it out and you are mostly correct! you can use document.write as often as you like. the problem is that I can pull the first value from the dropdown control but once I document.write that value to the new page, I am unable to reference that same control because it no longer exists. in this case I must compile all of my values first then write to the page...

thanks for pointing me in the right direction. problem solved!

[Dormilich]

in this case I must compile all of my values first then write to the page...

…or use a more appropriate method like DOM.

[gits]

…or use a more appropriate method like DOM

that way is definitly to prefer, document.write( ) shouldn't be used or when it has to ... then at least with the corresponding open() and close() methods.

kind regards

[yarbrough40]

thanks - I really have no reason to use document.write. this was only used as a test to see if I could get at the values. it is a common practice in .net using response.write. the difference is that response.write does not instantiate a new page so the data objects you reference will persist and no errors will occur. It's a simple matter of understanding my environment : )

[acoder]

is there perhaps some kind of fundamental Java violation...

Sorry to be picky, but it's important. Java and JavaScript are two very different languages. It's important to make the distinction.