Javascript Error (Line: 1 Char: 1 Error: Object Expected Code: 0)

[whatelyb]

I am having trouble related to the attached coding.

I am trying to make the object "flight1pic " change depending on what is selected in the drop down menus "airline1" and "aircraft1" .

My problem is when changing "airline1" it all works fine, but when changing "aircraft1" i get the error:

Line: 1
Char: 1
Error: Object Expected
Code: 0

function flightpicFunction(){
	if(document.getElementById('airline1').value == "Qantaslink" && document.getElementById('aircraft1').value == "Boeing 717"){ document.getElementById('flight1pic').innerHTML = "<img src=../images/aircraft/QF_B717.jpg>"; }
	if(document.getElementById('airline1').value == "Skywest" && document.getElementById('aircraft1').value == "Fokker 100"){ document.getElementById('flight1pic').innerHTML = "<img src=../images/aircraft/XR_F100.jpg>"; }
}

Can anyone tell me what i might be doing wrong?

<select size="1" onChange="flightpicFunction();" name="aircraft1" tabindex="3">
  <option value="BAe 146">BAe 146</option>
  <option value="Boeing 717">Boeing 717</option>
  <option value="Boeing 737">Boeing 737</option>
  <option value="Dash 8">Dash 8</option>
  <option value="Embraer 120">Embraer 120</option>
  <option value="Embraer 145">Embraer 145</option>
  <option value="Embraer 170">Embraer 170</option>
  <option value="Embraer 190">Embraer 190</option>
  <option value="Fokker 100">Fokker 100</option>
  <option value="Fokker 50">Fokker 50</option>
  <option value="Other">Other</option>
</select>

[Frinavale]

I've moved your question from the Java forum into the JavaScript forum where you will find more help with your JavaScript question.


Select HTML elements consist of a bunch of options.
It doesn't make sense to set a select HTML element's "value" property because it doesn't have a value....it has a bunch of options.

-Frinny

[whatelyb]

I've moved your question from the Java forum into the JavaScript forum where you will find more help with your JavaScript question.


Select HTML elements consist of a bunch of options.
It doesn't make sense to set a select HTML element's "value" property because it doesn't have a value....it has a bunch of options.

-Frinny

Sorry, can you explain it to me in lamens (easy) terms? I'm good with PHP but I really haven't the slightest clue with Javascript.

[whatelyb]

I have tried replacing the code:

document.getElementById('aircraft1').value

with this code:

document.navform.aircraft1.options[document.navform.aircraft1.selectedIndex].value

And I still get the same error. :(

[whatelyb]

Sorry to mess you around. The problem turned out to be my PHP coding.

The PHP coding I had set up changed which javascript function the dropdown menu called up, to one that didn't exist.

All works fine now. Thanks.

[thesmithman]

You are on the right track with selectedIndex.

try something like:

var dropdown = document.forms[0].aircraft1;
var selection = dropdown[dropdown.selectedIndex].value;

Here's a reference for more information:

http://www.w3schools.com/jsref/prop_select_selectedindex.asp

And by the way, I highly recommend doing your JavaScript debugging in a different browser. Those Internet Explorer error messages just aren't that helpful. There is a handy plugin for Firefox called Firebug; and there are developer tools built in to the Chrome browser.

Happy coding!

[thesmithman]

I see you got it sorted out before I hit the "post reply" button! Glad to hear it.

[whatelyb]

Yeah thanx anyway "thesmithma n" and also "Frinavale" . I suppose the best diagnosis is a good night sleep. Was trying to figure it all out at 2am in the morning (before I relised what time it was.)

[Frinavale]

Internet Explorer 8 comes with a debugger (hit F12).
If you like FireFox then download a plugin called FireBug.

-Frinny

[Dormilich]

two things from my side.

your <select> does not have an ID, so trying to access it with getElementById( ) will only work in IE (given the name is unique, too).

second, a <select> indeed has a value property, which you can read and write.