var timelinePs = new Array();

    //timelinePs = getElementsByClass("timelineEntry");
    

    function getElementsByClass(searchClass) {

       alert ("This getElementsByClass");
  	   var classElements = new Array();
  	   var els = document.getElementsByTagName("*");
  	   var elsLen = els.length;
       alert (elsLen);
  	   var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
  	   var j = 0;
  	   for (i = 0; i < elsLen; i++) {
          alert(els[i]);
  		    if (pattern.test(els[i].className) ) {
  			     classElements[j] = els[i];
  			     j++;
  		    }
  	   }
  	   alert (j);
  	   return classElements;
    }


    function procEntries(){
      // browse the dom and truncate the <p class="timelineEntry"> tags
      
    }
    function truncEntry(entryStr){
       var maxChars = 200;
       if (entryStr.length>maxChars){
          entryStr = entryStr.substring(0,maxChars);
       }
       return entryStr;
    }

    function setPageTitle(titleStr){
        document.title = titleStr;
    }
    function setPageTitleDates(titleStr, sYear, eYear){
        document.title = titleStr+" "+sYear;
    }

    function updateEvents(x) {
      var etVal = document.getElementById('categoriesForm_et').value;
      var newEtVal = 0;
      var countTicked = 0

      if (document.getElementById('categoriesForm_regs').checked){ newEtVal=newEtVal+1; countTicked++;}
      if (document.getElementById('categoriesForm_films').checked){ newEtVal=newEtVal+2; countTicked++;}
      if (document.getElementById('categoriesForm_gov').checked){ newEtVal=newEtVal+4; countTicked++;}
      if (document.getElementById('categoriesForm_ind').checked){ newEtVal=newEtVal+8; countTicked++;}
      if (document.getElementById('categoriesForm_peop').checked){ newEtVal=newEtVal+16; countTicked++;}
      if (document.getElementById('categoriesForm_hist').checked){ newEtVal=newEtVal+32; countTicked++;}

      document.getElementById('categoriesForm_et').value = newEtVal;

      //if only one box ticked disable unticking last option
      if (countTicked==1){
        // find the one that's ticked and disable it
          if (document.getElementById('categoriesForm_regs').checked) document.getElementById('categoriesForm_regs').disabled=true;
          if (document.getElementById('categoriesForm_films').checked) document.getElementById('categoriesForm_films').disabled=true;
          if (document.getElementById('categoriesForm_gov').checked) document.getElementById('categoriesForm_gov').disabled=true;
          if (document.getElementById('categoriesForm_ind').checked) document.getElementById('categoriesForm_ind').disabled=true;
          if (document.getElementById('categoriesForm_peop').checked) document.getElementById('categoriesForm_peop').disabled=true;
          if (document.getElementById('categoriesForm_hist').checked) document.getElementById('categoriesForm_hist').disabled=true;
      } else {
          document.getElementById('categoriesForm_regs').disabled=false;
          document.getElementById('categoriesForm_films').disabled=false;
          document.getElementById('categoriesForm_gov').disabled=false;
          document.getElementById('categoriesForm_ind').disabled=false;
          document.getElementById('categoriesForm_peop').disabled=false;
          document.getElementById('categoriesForm_hist').disabled=false;
      }
    }