For example
<input type="text" name="disp">
<input type="button" name="but0" value="0" onclick=""+"calc.disp.value=0"+"">
Here if I click the button 0 means it should display the 0 in text box. If I click the button it should concatenate in that box. But it replaces that is the code is wrong.
As far as I understand it, you want each button click to add 0 to the text box contents. So it starts out empty, and when you push the button the first time, the contents changes to 0. Pushing it a second time changes the contents to 00.
Assuming that's correct, try this:
<input type="text" name="disp">
<input type="button" name="but0" value="0" onclick="calc.disp.value=calc.disp.value + '0';">
If you are allowed to use jQuery I would suggest that as the code needed then becomes a lot easier to see what is going on:
First add an id attribute to each input.
<input type="text" name="disp" id="textBox">
<input id="button0" type="button" name="but0" value="0">
you want to add 0s? so if you entered 1 then you hit the 0 button it will show 10 then again will change to 100:
<script type="text/ecmascript">
$(document).ready(function()
{
$("#button0").click(function()
{
var textVal = $("#textBox").val();
$("#textBox").val(textVal + 0);
});
});
</script>
Hi you can do it by following way
<input type="text" name="tst" id="tst">
<input type="button" value="0" onclick="javascript:document.getElementById('tst').value = document.getElementById('tst').value + this.value "
javascipt: in event handlers, and don't call ´getElementById` twice.var sum = document.getElementById("id1").value
+ document.getElementById("id2").value
+ document.getElementById("id3").value;
