Can I immediately call a function when selecting data in a SharePoint 2010 choice field?

Question

I am trying to show/hide other fields depending on the choice selected from a specific choice field in my SharePoint form (NOT InfoPath). I can get it to work using "onfocusout" but that does not work in Firefox, and it doesn't call the function until after I select the item and then click off of the box. This could confuse users, so I need it to call the function immediately upon selection of a choice.

I am using SharePoint 2010 (and Designer 2010) and I need it to work on Firefox and IE8. Yeah, I know IE8 is REALLY old, but I don't have a choice. Any help would be appreciated!

Here's what I am using (it is contained inside of a table td):

  <div onfocusout="showFields()">
      <SharePoint:FormField runat="server" id="ff15{$Pos}" ControlMode="New" FieldName="Account_x0020_Type" __designer:bind="{ddwrt:DataBind('i',concat('ff15',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@Account_x0020_Type')}"/>
      <SharePoint:FieldDescription runat="server" id="ff15description{$Pos}" FieldName="Account_x0020_Type" ControlMode="New"/>
  </div>

Then the function is as follows:

function showFields() {
var accountType = $('#ctl00_m_g_de548742_27f6_4e71_b3ec_2d9a1ecca117_ff151_ctl00_DropDownChoice').val();

 if(accountType == 'Military') {
    $('.milShow').show();
    $('.ctrShow').hide();
    $('.civShow').hide();
 }
 if(accountType == 'Government Civilian') {
    $('.civShow').show();
    $('.ctrShow').hide();
    $('.milShow').hide();
 }
 if(accountType == 'Contractor') {
    $('.ctrShow').show();
    $('.milShow').hide();
    $('.civShow').hide();
 }
}

Answer 1

Try this

$(document).ready(function(){
    $('#ctl00_m_g_de548742_27f6_4e71_b3ec_2d9a1ecca117_ff151_ctl00_DropDownChoice').on('change', function(){
        var accountType = this.value;
        if(accountType == 'Military') {
            $('.milShow').show();
            $('.ctrShow').hide();
            $('.civShow').hide();
        }
        if(accountType == 'Government Civilian') {
            $('.civShow').show();
            $('.ctrShow').hide();
            $('.milShow').hide();
        }
        if(accountType == 'Contractor') {
            $('.ctrShow').show();
            $('.milShow').hide();
            $('.civShow').hide();
        }
    });
});