What's wrong with my HTML and javascript code?
Question
I want to implement a simple measurement convergence program but the convert button doesn't really work and it's not even changing the value of the answer box. What should I do now?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Measurement Conversion</title>
</head>
<body>
<h1 align="center">
Measurement Conversion
</h1>
<div align="center"><center><table border="0">
<tr>
<input type="text" name="what" size="15">
</tr>
<tr>
<td align="center">From:<br>
<select name="unit" size="9" onChange="convert()">
<option name="meter">meter</option>
<option name="mile">mile</option>
<option name="yard">yard</option>
</select></td>
</tr>
<tr>
<input type="button" onclick="convert()">Convert it now!</button></td>
</tr>
<tr>
<input type="text" name="answer" title="answer" size="70" value="None"></td>
</tr>
</table>
</center></div>
<script>
function convert() {
// var FromVal, ToVal, FromName, ToName, v1;
v1 = document.getElementByName("what").value;
document.getElementByName("answer").value = v1;
var unit = document.getElementByName("unit").name;
if (unit == "yard") {
var meter = "meter= " + 0.9144*document.getElementByName("what").value;
var mile = "mile = " + 0.000568181818*document.getElementByName("what").value;
document.getElementById("answer").value = meter + mile;
}
if (unit == "meter") {
var yard = "yard = " + 1.0936133*document.getElementByName("what").value;
var mile = "mile = " + 0.000621371192*document.getElementByName("what").value;
// var meter = "m = " + 0.9144*document.getElementByName("what").value
document.getElementById("answer").value = yard + mile;
}
if (unit == "mile") {
var meter = "meter = " + 1609.344*document.getElementByName("what").value
var yard = "yard = " + 1760*document.getElementByName("what").value
document.getElementById("answer").value = meter + yard;
}
}
</script>
</body>
</html>
It seems there is something wrong with my convert() function.
2 answers
solution1
2 ACCPTED 2016-09-14 01:17:00
How about using the most basic troubleshooting methods first and then coming here and asking specific questions to help get you through the problem. Add an alert("button Clicked"); to the first line of your function and see if you get the alert. If you do, move the alert to after your variable statements and change it to alert("what = " + what + ", "answer = " + answer + ", unit = " + unit); and make sure you are getting what you expect for your variable assignments. Continue like this and when you get to a specific problem that your can't seem to remedy yourself, come back.
solution2
1 2016-09-14 01:08:11
there's no getElementByName. add attribute id on your input then use getElementById instead.
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