Drop down boxes and javascript - How to get the value

[ahbenshaut]

Good Day to all!
I am working on a function that is making my head hurt. I know it's something simple so hopefully one of you great people will point me in the right direction:
I created this function:

        
function getCompanyFaxAndPhone(document.getElementById('ddlCompanyName').value) {
            Case "None":
                //None Selected
                document.PayoffEForm.txtPhoneNumber.value = '';
                document.PayoffEForm.txtFaxNumber.value = '';
                break;
            Case "Alaska Escrow & Title Insurance":
                document.PayoffEForm.txtPhoneNumber.value = "somePhone";
                document.PayoffEForm.txtFaxNumber.value = "someFax";
                break;
        }

that is to be used on an onchange event of the drop down list, like so:
<select id="ddlCompanyName" name="ddlCompanyName" onchange="getCompanyFaxAndPhone()">
<option value="None">None</option>
<option value="something1">something1</option>
<option value="something2">something2</option>
<option value="something3">something3</option>
</select>

It "looks" right but when I run it, I get the "Object Expected" error on the onchange event....

help!

thanks a bunch