onChange problem with two dropdowns and one form

Phil Powell · Sep 24, 2003

I have a form with two single-choice dropdowns. Upon doing an onChange
event on either one of them, I want to check to see if the other dropdown
has also been selected. How would I do that, considering that this.parent
causes an error "null or not an object"?

Thanx
Phil

Lee · Sep 25, 2003

Phil Powell said:

I have a form with two single-choice dropdowns. Upon doing an onChange
event on either one of them, I want to check to see if the other dropdown
has also been selected. How would I do that, considering that this.parent
causes an error "null or not an object"?

The "parent" attribute is an attribute of windows.
Form elements have an attribute named "form", which is a reference
to the containing form.

<html>
<head>
<script type="text/javascript">
function seeIfBothChosen(f){
if(f.select1.selectedIndex && f.select2.selectedIndex){
alert(f.select1.options[f.select1.selectedIndex].text + " / " +
f.select2.options[f.select2.selectedIndex].text);
}
}
</script>
</head>
<body>
<form>
<select name="select1" onchange="seeIfBothChosen(this.form)">
<option>--Choose--</option>
<option>alpha</option>
<option>beta</option>
</select>
<select name="select2" onchange="seeIfBothChosen(this.form)">
<option>--Choose--</option>
<option>gamma</option>
<option>delta</option>
</select>
</form>
</body>
</html>

Phil Powell · Sep 25, 2003

Ok cool, is there then an easier way to check then that if one dropdown has
been selected that so has the other within the same form?

Thanx
Phil

Lee said:
Phil Powell said:

I have a form with two single-choice dropdowns. Upon doing an onChange
event on either one of them, I want to check to see if the other dropdown
has also been selected. How would I do that, considering that this.parent
causes an error "null or not an object"?

Click to expand...

The "parent" attribute is an attribute of windows.
Form elements have an attribute named "form", which is a reference
to the containing form.

<html>
<head>
<script type="text/javascript">
function seeIfBothChosen(f){
if(f.select1.selectedIndex && f.select2.selectedIndex){
alert(f.select1.options[f.select1.selectedIndex].text + " / " +
f.select2.options[f.select2.selectedIndex].text);
}
}
</script>
</head>
<body>
<form>
<select name="select1" onchange="seeIfBothChosen(this.form)">
<option>--Choose--</option>
<option>alpha</option>
<option>beta</option>
</select>
<select name="select2" onchange="seeIfBothChosen(this.form)">
<option>--Choose--</option>
<option>gamma</option>
<option>delta</option>
</select>
</form>
</body>
</html>

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onChange problem with two dropdowns and one form

Phil Powell

Lee

Phil Powell

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