Q:

Accommodation checking assignment

We have an assignment to make a basic tour cost calculator using a combination of javascript and html.  I was fixing errors using the developer console when suddenly the errors all vanished, along with all content on the page.  Nothing loads anymore. 
I've tried removing certain parts of the code one at a time to try and find what is causing this, but i can't find anything.  Can anyone spot the problem(s) thats causing this?  Thanks! 
<script>
var dailycost = 0;
var radiobutton;
var checkbox;
var duration = 0;
var total = 0;

function getcost(){
        for (var i = 1; i<=3; i++){
            radiobutton = document.getElementByID("accomodation" + i);
            if (radiobutton.checked == true){
                dailycost = radiobutton.value;
            }
        }
        if (dailycost == 0){
            alert("No accomodation type was selected."); 
            return;
        }

    checkbox = document.getElementByID("peakSeason");
        if (checkbox.checked == true){
            dailyCost = parseFloat(dailycost) + 20;
        }
        for (var i = 1; i <= 4; i++){
            radiobutton = document.getElementByID("duration");
            if (radiobutton.checked == true){
            duration = radioButton.value;
            }
        }
        if (duration == 0){
            alert("A duration was not selected."); 
            return;
    }
        totalcost = dailycost * duration;
        totalcost = math.round(totalcost);
        alert("This tour will cost " + totalcost +'$');
    }
</script>

A:

There was so many various typos/mistakes.  Fixes are below:

radiobutton ! = radioButton
missing ID's for accomodation
missing + i after duration
math.round ! = Math.round

    var dailycost = 0;
    var radiobutton;
    var checkbox;
    var duration = 0;
    var total = 0;

 function getcost(){
      for (var i = 1; i<=3; i++){
             radiobutton = document.getElementById("accomodation" + i);
       if (radiobutton.checked == true){
        dailycost = radiobutton.value;
       }
      }
      if (dailycost == 0){
       alert("No accomodation type was selected."); 
       return;
      }
    
      checkbox = document.getElementById("peakseason");
      if (checkbox.checked == true){
       dailycost = parseFloat(dailycost) + 20;
      }
      for (var i = 1; i <= 4; i++){
       radiobutton = document.getElementById("duration" + i);
       if (radiobutton.checked == true){
    duration = radiobutton.value;
       }
      }
      if (duration == 0){
       alert("A duration was not selected."); 
       return;
  }
      totalcost = dailycost * duration;
      totalcost = Math.round(totalcost);
      alert("This tour will cost " + totalcost +'$');
     }
<h1>USA Tour Cost Calculator</h1>
<h4>Complete the following form to calculate the cost of your tour.</h4>
<form name="tourform">
<p>Accomodation Type:<br>
<input type="radio" name="accomodation" id="accomodation1" value="95.5"> Camping<br>
<input type="radio" name="accomodation" id="accomodation2" value="140.3"> Budget Hotel<br>
<input type="radio" name="accomodation" id="accomodation3" value="170.7"> Premier Hotel<br>
 
<p><label for="peakseason">Click here if you are traveling between June and August.</label>
<input type="checkbox" id="peakseason" name="peakseason"></p>
 
<p>Tour Duration:<br>
<input type ="radio" name="duration" id="duration1" value="4"> <label for="duration1">4 days</label><br>
<input type ="radio" name="duration" id="duration2" value="7"> <label for="duration1">7 days</label><br>
<input type ="radio" name="duration" id="duration3" value="14"> <label for="duration1">14 days</label><br>
<input type ="radio" name="duration" id="duration4" value="20"> <label for="duration1">20 days</label><br><br>
 
<input type ="button" value ="Calculate" onClick="getcost();">
<input type ="reset" value ="Reset"></p>
</form>

I'd simplify it though, to the below (Drop the loops, avoid having to ID every input, and avoid adding variables outside the function):

function getcost(){
  const acc = document.querySelectorAll('input[name=accomodation]:checked');
  
  if (! acc.length) {
    alert("No accomodation type was selected."); 
    return;
  }
  
  let dailycost = parseFloat(acc[0].value);

  const checkbox = document.getElementById("peakseason");
  if (checkbox.checked){
    dailycost += 20;
  }
  
  const durationInput = document.querySelectorAll('input[name=duration]:checked');
  
  if (! durationInput.length) {
    alert("A duration was not selected."); 
    return;
  }
  
  const duration = durationInput[0].value;
  
  const totalcost = Math.round(dailycost * duration);
  alert("This tour will cost " + totalcost +'$');
}
<h1>USA Tour Cost Calculator</h1>
<h4>Complete the following form to calculate the cost of your tour.</h4>
<form name="tourform">
<p>Accomodation Type:<br>
<input type="radio" name="accomodation" value="95.5"> Camping<br>
<input type="radio" name="accomodation" value="140.3"> Budget Hotel<br>
<input type="radio" name="accomodation" value="170.7"> Premier Hotel<br>
 
<p><label for="peakseason">Click here if you are traveling between June and August.</label>
<input type="checkbox" id="peakseason" name="peakseason"></p>
 
<p>Tour Duration:<br>
<input type ="radio" name="duration" value="4"> <label for="duration1">4 days</label><br>
<input type ="radio" name="duration" value="7"> <label for="duration1">7 days</label><br>
<input type ="radio" name="duration" value="14"> <label for="duration1">14 days</label><br>
<input type ="radio" name="duration" value="20"> <label for="duration1">20 days</label><br><br>
 
<input type ="button" value="Calculate" onClick="getcost();">
<input type ="reset" value="Reset"></p>
</form>

