I have a simple HTML form, with 3 input field, when you hit = button, it suppose to add 2 numbers that you typed in the first 2 input fields and display result in 3rd filed.
<HTML>
<HEAD>
<TITLE>Sum</TITLE>
<script type="text/javascript">
function sum()
{
var num1 = document.myform.number1.value;
var num2 = document.myform.number2.value;
var sum = parseInt(num1) + parseInt(num2);
document.getElementById('add').value = sum;
}
</script>
</HEAD>
<BODY>
<FORM NAME="myform">
<INPUT TYPE="text" NAME="number1" VALUE=""/> +
<INPUT TYPE="text" NAME="number2" VALUE=""/>
<INPUT TYPE="button" NAME="button" Value="=" onClick="sum()"/>
<INPUT TYPE="text" ID="add" NAME="result" VALUE=""/>
</FORM>
</BODY>
</HTML>
This should work properly. 1. use .value instead of "innerHTML" when setting the 3rd field (input field) 2. Close the input tags
<HTML>
<HEAD>
<TITLE>Sum</TITLE>
<script type="text/javascript">
function sum()
{
var num1 = document.myform.number1.value;
var num2 = document.myform.number2.value;
var sum = parseInt(num1) + parseInt(num2);
document.getElementById('add').value = sum;
}
</script>
</HEAD>
<BODY>
<FORM NAME="myform">
<INPUT TYPE="text" NAME="number1" VALUE=""/> +
<INPUT TYPE="text" NAME="number2" VALUE=""/>
<INPUT TYPE="button" NAME="button" Value="=" onClick="sum()"/>
<INPUT TYPE="text" ID="add" NAME="result" VALUE=""/>
</FORM>
</BODY>
</HTML>
<HTML>
<HEAD>
<TITLE>Sum</TITLE>
<script type="text/javascript">
function sum()
{
var num1 = document.myform.number1.value;
var num2 = document.myform.number2.value;
var sum = parseInt(num1) + parseInt(num2);
document.getElementById('add').innerHTML = sum;
}
</script>
</HEAD>
<BODY>
<FORM NAME="myform">
<INPUT TYPE="text" NAME="number1" VALUE=""/> +
<INPUT TYPE="text" NAME="number2" VALUE=""/>
<INPUT TYPE="button" NAME="button" Value="=" onClick="sum()"/>
<DIV ID="add"></DIV>
</FORM>
</BODY>
</HTML>
innerHTML
sets the text (including html elements) inside an element. Normally we use it for elements like div, span etc to insert other html elements inside it.
For your case you want to set the value of an input element. So you should use the value
attribute.
Change innerHTML
to value
document.getElementById('add').value = sum;
Do you really want the result to come up in an input box? If not, consider a table with borders set to other than transparent and use
document.getElementById('sum').innerHTML = sum;