Activate Onchange function with VBA in URL

I have to fill forms inside a web site using excel. The site works like this - when choosing something from a combobox then new input boxes are activated with onchange function as below code.

<select name="murat" id="murat" class="normalText" onchange="muratonChange(this);">

function muratonChange(source) {
  var muratIndex, Visibility;
  muratIndex=source.selectedIndex
  document.all.ayaz.style.visibility="visible";

I can select anything inside combobox. However, input boxes are not becoming visible so I cannot change them. Using below vba code to assign value to combobox

While .Busy Or .readyState < 4: DoEvents: Wend

        Do
            DoEvents
            On Error Resume Next
            Set ele = ie.document.querySelector("murat")
            On Error GoTo 0
            If Timer - t > MAX_WAIT_SEC Then Exit Do
        Loop While ele Is Nothing
        If Not ele Is Nothing Then
            ele.Click                            
            ie.document.getElementsByName("murat")(0).Value = Application.VLookup(Sheets("fener").Range("D3").Text, Sheets("bahce").Range("A:B"), 2, False)
        End If

Also I would appreciate it if anyone can check another of my questions at below link.

VBA - Skip Login Page if site is already logged in IE