我是JavaScript的新手，我正在尝试根据班级类型，居住时间和学时确定学费和费用的成本估算器。我有学费，但不知道如何计算费用。 fees.png
如果其他方法不起作用，请尝试我能想到的一切。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Untitled Document</title>
<script type="text/javascript">
function formHandler(form) {
var tuition1 = eval(form.tuition1.value);
var tuition2 = eval(form.tuition2.value);
var tuition3 = eval(form.tuition3.value);
var hours1 = eval(form.hours1.value);
var hours2 = eval(form.hours2.value);
var hours3 = eval(form.hours3.value);
var t1 = tuition1 * hours1;
var t2 = tuition2 * hours2;
var t3 = tuition3 * hours3;
var oncfee1 = 0;
var olcfee1 = 0;
var cjusfee1 = 0;
//Calculate on campus fees
if (hours1 === "1") {
oncfee1 = 95.25;
} else if (hours1 === "2") {
oncfee1 = 123.5;
} else if (hours1 === "3") {
oncfee1 = 151.75;
} else if (hours1 === "4") {
oncfee1 = 237.5;
} else if (hours1 === "5") {
oncfee1 = 265.75;
} else if (hours1 === "6") {
oncfee1 = 294.0;
} else if (hours1 === "7") {
oncfee1 = 549.25;
} else if (hours1 === "8") {
oncfee1 = 577.5;
} else if (hours1 === "9") {
oncfee1 = 605.75;
} else if (hours1 === "10") {
oncfee1 = 634.0;
} else if (hours1 === "11") {
oncfee1 = 662.25;
} else if (hours1 === "12") {
oncfee1 = 690.5;
} else if (hours1 === "13") {
oncfee1 = 718.75;
} else if (hours1 === "14") {
oncfee1 = 747.0;
} else if (hours1 === "15") {
oncfee1 = 775.25;
} else if (hours1 === "16") {
oncfee1 = 792.5;
} else if (hours1 === "17") {
oncfee1 = 809.75;
} else if (hours1 === "18") {
oncfee1 = 827.0;
} else if (hours1 === "19") {
oncfee1 = 844.25;
} else if (hours1 === "20") {
oncfee1 = 861.5;
} else if (hours1 === "21") {
oncfee1 = 878.75;
} else {
oncfee1 = 0;
}
//Calculate online fees
if (hours2 === "1") {
olcfee1 = 61.25;
} else if (hours2 === "2") {
olcfee1 = 118.5;
} else if (hours2 === "3") {
olcfee1 = 175.75;
} else if (hours2 === "4") {
olcfee1 = 233.0;
} else if (hours2 === "5") {
olcfee1 = 290.25;
} else if (hours2 === "6") {
olcfee1 = 347.5;
} else if (hours2 === "7") {
olcfee1 = 404.75;
} else if (hours2 === "8") {
olcfee1 = 462.0;
} else if (hours2 === "9") {
olcfee1 = 519.25;
} else if (hours2 === "10") {
olcfee1 = 576.5;
} else if (hours2 === "11") {
olcfee1 = 633.75;
} else if (hours2 === "12") {
olcfee1 = 691.0;
} else if (hours2 === "13") {
olcfee1 = 748.25;
} else if (hours2 === "14") {
olcfee1 = 805.5;
} else if (hours2 === "15") {
olcfee1 = 862.75;
} else {
olcfee1 = 0;
}
//Calculate CJUS online fees
if (hours3 === "1") {
cjusfee1 = 61.25;
} else if (hours3 === "2") {
cjusfee1 = 118.5;
} else if (hours3 === "3") {
cjusfee1 = 175.75;
} else if (hours3 === "4") {
cjusfee1 = 233.0;
} else if (hours3 === "5") {
cjusfee1 = 290.25;
} else if (hours3 === "6") {
cjusfee1 = 347.5;
} else if (hours3 === "7") {
cjusfee1 = 404.75;
} else if (hours3 === "8") {
cjusfee1 = 462.0;
} else if (hours3 === "9") {
cjusfee1 = 519.25;
} else if (hours3 === "10") {
cjusfee1 = 576.5;
} else if (hours3 === "11") {
cjusfee1 = 633.75;
} else if (hours3 === "12") {
cjusfee1 = 691.0;
} else if (hours3 === "13") {
cjusfee1 = 748.25;
} else if (hours3 === "14") {
cjusfee1 = 805.5;
} else if (hours3 === "15") {
cjusfee1 = 862.75;
} else {
cjusfee1 = 0;
}
var fees = oncfee1 + olcfee1 + cjusfee1;
var cost = t1 + t2 + t3 + fees;
form.t1.value = "$" + t1;
form.t2.value = "$" + t2;
form.t3.value = "$" + t3;
form.fees.value = "$" + fees;
form.costresult.value = "$" + cost;
}
</script>
</head>
<body>
<form method="post" name="testform">
<div>
<table
id="AutoNumber1"
summary="calculate the cost per semester for
undergraduate students"
>
<tbody>
<tr>
<td colspan="2">
<label for="tuition1">On campus class tuition </label>
<select id="tuition1" name="tuition1">
<option selected="selected" value="0">None</option>
<option value="203">Resident</option>
<option value="443">Non Resident</option>
</select>
</td>
</tr>
<tr>
<td colspan="2">
<label for="hours1"
>Enter number of On campus credit hours
</label>
<input
id="hours1"
name="hours1"
size="5"
type="text"
value="0"
/>
</td>
</tr>
<br />
<tr>
<td colspan="2">
<label for="tuition2">Online or Blended class</label
> <select id="tuition2" name="tuition2">
<option selected="selected" value="0">None</option>
<option value="261">Online/Blended class Resident</option>
<option value="396">Online/Blended class Non Resident</option>
</select>
</td>
</tr>
<tr>
<td colspan="2">
<label for="hours2"
>Enter number of Online or Blended credit hours
</label>
<input
id="hours2"
name="hours2"
size="5"
type="text"
value="0"
/>
</td>
</tr>
<br />
<tr>
<td colspan="2">
<label for="tuition3"
>Online or Blended Criminal Justice class</label
> <select id="tuition3" name="tuition3">
<option selected="selected" value="0">None</option>
<option value="280"
>Online/Blended Criminal Justice class Resident</option
>
<option value="405"
>Online/Blended Criminal Justice class Non Resident</option
>
</select>
</td>
</tr>
<tr>
<td colspan="2">
<label for="hours3"
>Enter number of Online or Blended Criminal Justice credit
hours</label
>
<input
id="hours3"
name="hours3"
size="5"
type="text"
value="0"
/>
</td>
</tr>
<tr>
<td colspan="2">
<p>
<button
name="CostResult"
onclick="javascript:formHandler(this.form)"
type="button"
>
Calculate Estimated Semester Cost
</button>
</p>
</td>
</tr>
<tr>
<td><label for="t1">Tuition On Campus Class</label></td>
<td><input id="t1" name="t1" size="10" type="text" /></td>
</tr>
<tr>
<td><label for="t2">Tuition Online / Blended Class</label></td>
<td><input id="t2" name="t2" size="10" type="text" /></td>
</tr>
<tr>
<td>
<label for="t3">Tuition Online / Blended CJUS Class</label>
</td>
<td><input id="t3" name="t3" size="10" type="text" /></td>
</tr>
<tr>
<td><label for="fees">Fees</label></td>
<td><input id="fees" name="fees" size="10" type="text" /></td>
</tr>
<tr>
<td>
<label for="costresult">Total Estimated Semester Cost</label>
</td>
<td>
<input
id="costresult"
name="costresult"
size="10"
type="text"
/>
</td>
</tr>
</tbody>
</table>
</div>
</form>
</body>
</html>
费用根据学时和班级类型而定。目前，我无法返回结果。我想退回全部费用。