Change function to take in class name

Change function to take in class name

I have a page that produces the following html.

Check all checkbox html:
<span class="chkHeader2"><input id="CPH1_dlYear_cbCheckAll" type="checkbox" name="ctl00$CPH1$dlYear$ctl00$cbCheckAll" checked="checked" /></span>

Check box controls being produced by my page:
<span class="chkItem2"><input id="CPH1_dlYear_chkYear_0" type="checkbox" name="ctl00$CPH1$dlYear$ctl01$chkYear" checked="checked" /></span>

<span class="chkItem2"><input id="CPH1_dlYear_chkYear_1" type="checkbox" name="ctl00$CPH1$dlYear$ctl02$chkYear" checked="checked" /></span>


I have multiple sets of this within my page with different class names. ex.  I have chkItem1, chkItem3 and the same with the chkHearder class.

I have this jquery function and want to know if it is possible to use this one function for all 3 sets of checkboxes?  I want each set to check all of their specific set of checkboxes not ones from any other set.

  1.  <script type="text/javascript">
        $(window).bind('load', function () {
          var headerChk = $(".chkHeader input");
          var itemChk = $(".chkItem input");

          headerChk.bind("click", function () {
            itemChk.each(function () {
              this.checked = headerChk[0].checked;
            })
          });

          var flag = false;
          itemChk.bind("click", function () {

            itemChk.each(function () {
              if (this.checked == false) {
                flag = false;
                return false;
              }
              else
                flag = true;
            })
            headerChk[0].checked = flag;
          });
        });

        //same version for partial postback
        Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(function (sender, args) {

          var headerChk = $(".chkHeader input");
          var itemChk = $(".chkItem input");

          headerChk.bind("click", function () {
            itemChk.each(function () {
              this.checked = headerChk[0].checked;
            })
          });

          var flag = false;
          itemChk.bind("click", function () {
            itemChk.each(function () {
              if (this.checked == false) {

                flag = false;
                return false;
              }
              else
                flag = true;
            })
            headerChk[0].checked = flag;
          });
        });
       </script>

Thank you