function show_course_information() {
   document.getElementById('sections_found').style.display = "none"
   document.getElementById('course_information').style.display = "block"
}
function show_sections_found() {
   document.getElementById('course_information').style.display = "none"
   document.getElementById('sections_found').style.display = "block"
}
function alldays(row) {
   document.getElementById(row+'m').checked = 'checked'
   document.getElementById(row+'t').checked = 'checked'
   document.getElementById(row+'w').checked = 'checked'
   document.getElementById(row+'r').checked = 'checked'
   document.getElementById(row+'f').checked = 'checked'
   document.getElementById(row+'s').checked = 'checked'
   document.getElementById(row+'u').checked = 'checked'
}
function weekdays(row) {
   document.getElementById(row+'m').checked = 'checked'
   document.getElementById(row+'t').checked = 'checked'
   document.getElementById(row+'w').checked = 'checked'
   document.getElementById(row+'r').checked = 'checked'
   document.getElementById(row+'f').checked = 'checked'
   document.getElementById(row+'s').checked = false
   document.getElementById(row+'u').checked = false
}
function weekends(row) {
   document.getElementById(row+'m').checked = false
   document.getElementById(row+'t').checked = false
   document.getElementById(row+'w').checked = false
   document.getElementById(row+'r').checked = false
   document.getElementById(row+'f').checked = false
   document.getElementById(row+'s').checked = 'checked'
   document.getElementById(row+'u').checked = 'checked'
}
function nodays(row) {
   document.getElementById(row+'m').checked = false
   document.getElementById(row+'t').checked = false
   document.getElementById(row+'w').checked = false
   document.getElementById(row+'r').checked = false
   document.getElementById(row+'f').checked = false
   document.getElementById(row+'s').checked = false
   document.getElementById(row+'u').checked = false
}
function numberOptions(prefix, term, year) {
   if (window.XMLHttpRequest) {
      req = new XMLHttpRequest()
   // branch for IE/Windows ActiveX version
   } else if (window.ActiveXObject) {
      req = new ActiveXObject("Microsoft.XMLHTTP")
   }
   if (req) {
      req.open("post", 
               "coursenumbers.rios",
               true)
      req.setRequestHeader("Content-Type", "text/xml")
      req.onreadystatechange=function() {
         if (req.readyState==4) {
            sel = document.getElementById('cor_number')
            clearSelect(sel)
            appendToSelect(sel, "", document.createTextNode("All Numbers"))
            nums = req.responseXML.getElementsByTagName('number')
            for (var x = 0; x < nums.length; x++) {
               appendToSelect(sel, nums[x].childNodes[0].nodeValue, document.createTextNode(nums[x].childNodes[0].nodeValue))
            }
         }
      }
      req.send("<?xml version=\"1.0\"?>\n<req_course_numbers><prefix>"+
               prefix+"</prefix><term>"+
               term+"</term><year>"+
               year+"</year></req_course_numbers>")
   }
}
function appendToSelect(select, value, content) {
   var opt
   opt = document.createElement("option")
   opt.value = value
   opt.appendChild(content)
   select.appendChild(opt)
}
function clearSelect(sel) {
   while (sel.length > 0) {
      sel.remove(0)
   }
}
function selectById(sid) {
   ele = document.getElementById(sid)
   if (!ele.checked) {
      ele.checked = 'checked'
   }
}
function godiffplaces(thingy) {
   window.open(thingy.options[thingy.selectedIndex].value)
}
// sid should be a string
function selectWithConflicts(sid, checkstate) {
   elm = document.getElementById("section"+sid)
   if (checkstate) {
      elm.checked = 'checked'
   } else {
      elm.checked = false
   }
   for (var x = 1; x < 50; x++) {
      con = document.getElementById("c"+x+"section"+sid)
      if (con) {
         if (checkstate) {
            con.checked = 'checked'
         } else {
            con.checked = false
         }
      }
   }
}

function numbersForPrefix(term, year) {
   corp = getElementById("cor_prefix")
   if (corp.value != "All Prefixes") {
      alert(corp.value)
      numberOptions(corp, term, year)
   }

}

// Functions to show and hide search elements for detailed
// or simple search
function detailSearch(count) {
        for (var x = 1; x <= count; x++){
	   document.getElementById("search"+x).style.display = 'block';
	}
	document.getElementById("detailedsearch").style.display = 'none';
	document.getElementById("simplesearch").style.display = 'inline';
}

function simpleSearch(count) {
        for (var x = 1; x <= count; x++){
	   document.getElementById("search"+x).style.display = 'none';
	}
	document.getElementById("simplesearch").style.display = 'none';
	document.getElementById("detailedsearch").style.display = 'inline';
}