Entry
How can I find the index of a FORM element in the elements array?
Mar 2nd, 2000 20:02
Martin Honnen,
Sometimes you might to find the index of a form field you know by its
name in the FORM's elements array. The following provides a function
getFormIndex
taking as the first argument a FORM object or a FORM name and as the
second argument the field name. It returns the index in the elements
array if the field is found or otherwise -1. An example form examining
itself is included.
<HTML>
<HEAD>
<SCRIPT>
function getFormIndex (form, fieldName) {
form = typeof form == 'string' ? document[form] : form;
var found = false;
for (var i = 0; i < form.elements.length; i++)
if ((found = form.elements[i].name == fieldName))
break;
return found ? i : -1;
}
</SCRIPT>
</HEAD>
<BODY>
<FORM NAME="aForm">
<INPUT TYPE="text" NAME="fieldName">
<INPUT TYPE="button" VALUE="get index" NAME="aButton"
ONCLICK="this.form.index.value = getFormIndex(this.form,
this.form.fieldName.value)">
<BR>
<INPUT TYPE="text" NAME="index" SIZE="4">
</FORM>
</BODY>
</HTML>
