Duplicate values in drop down list box

marx · Nov 17, 2003

I have a bit of a problem and any help would be much appreciated.

Problem: I have two dropdown list boxes with same data(all data
driven).
These are used for two separate entries.
For every entry you cannot choose the same value twice.
For example, I cannot choose for entry 1 the same
value in both selection boxes (gqCategory1Entry1 and
gqCategory2Entry1)

This part works.
The second entry is the problem: When I choose a value for Entry
Two that is the same as in entry one it thinks that "Dubplicate
Divisons have been selected").

WHen in fact these are two separate entries.

Code:
<head>
//Enry number one...no Duplicates
function check_selection(elt){
//check for duplicate selections
var form=elt.form;
var name=elt.name;
var index=elt.selectedIndex
//loop through all form elements
for(var i=0;i<form.length;i++){
var_name=form.elements.name;
var_index=form.elements.selectedIndex;
if(var_name.substring(0,16)!='gqCategory'){
// if form element is not the current element
// and the division name is the same, raise
//error message
if(var_name!=name&&index!=0&&var_index==index){
alert(var_name);
alert("Duplicate divisions selected! Please choose again.");
elt.selectedIndex=0;
elt.focus();
return false;
}
}
}
return true;
}

</head>

Entry one:
<select name="gqCategory1Entry1" maxlength="48" tabindex = 20
onChange="check_selection(this)" maxlength="48">
<option value="-1"> ---Select a Category---
<option value=1.1 > Division - 1.1 - Internet Sites
<option value=1.2 > Division - 1.2 - Intranet Sites
<option value=1.3 > Division - 1.3 - Interactive communication
</select>
<select name="gqCategory2Entry1" maxlength="48" tabindex = 20
onChange="check_selection(this)" maxlength="48">
<option value="-1"> ---Select a Category---
<option value=1.1 > Division - 1.1 - Internet Sites
<option value=1.2 > Division - 1.2 - Intranet Sites
<option value=1.3 > Division - 1.3 - Interactive communication
</select>
------------
Entry TWO:
<select name="gqCategory1Entry2" maxlength="48" tabindex = 20
onChange="check_selection(this)" maxlength="48">
<option value="-1"> ---Select a Category---
<option value=1.1 > Division - 1.1 - Internet Sites
<option value=1.2 > Division - 1.2 - Intranet Sites
<option value=1.3 > Division - 1.3 - Interactive communication
</select>
<select name="gqCategory2Entry2" maxlength="48" tabindex = 20
onChange="check_selection(this)" maxlength="48">
<option value="-1"> ---Select a Category---
<option value=1.1 > Division - 1.1 - Internet Sites
<option value=1.2 > Division - 1.2 - Intranet Sites
<option value=1.3 > Division - 1.3 - Interactive communication
</select>

Lasse Reichstein Nielsen · Nov 17, 2003

I have a bit of a problem and any help would be much appreciated.

Problem: I have two dropdown list boxes with same data(all data
driven).

You have two select elements with identical options.

These are used for two separate entries.

I.e., you have *four* select elements with identical options,
grouped into two "entries".

For every entry you cannot choose the same value twice.
For example, I cannot choose for entry 1 the same
value in both selection boxes (gqCategory1Entry1 and
gqCategory2Entry1)

This part works.
The second entry is the problem: When I choose a value for Entry
Two that is the same as in entry one it thinks that "Dubplicate
Divisons have been selected").

So the code checks all select elements, not only the ones in the same
"entry".

WHen in fact these are two separate entries.

Code:
<head>
//Enry number one...no Duplicates
function check_selection(elt){
//check for duplicate selections
var form=elt.form;
var name=elt.name;
var index=elt.selectedIndex
//loop through all form elements
for(var i=0;i<form.length;i++){
var_name=form.elements.name;
var_index=form.elements.selectedIndex;

These variables are not declared, so they become global variables.
No need for that. Put a "var" in front.

if(var_name.substring(0,16)!='gqCategory'){

Click to expand...

You only check that they have the same first 16 characters. That misses
the distinction between entries, which is much later in the name.

Example names:
gqCategory1Entry2
gqCategory1Entry1

The entry number is past the first 16 characters, and is never checked.

In case you ever need more than 9 or 10 categories or entries, let's
make this work for any number:

---
function check_selection(elt){
var gqCategoryRE = /^gqCategory(\d+)Entry(\d+)$/;
var index = elt.selectedIndex;
if (index == 0) {return true;} // always legal
var match = elt.name.match(gqCategoryRE);
if (!match) { return; } // not a gqCategory at all.
var category = +match[1];
var entry = +match[2];

var elems = elt.form.elements;
for (var i=0;i<elems.length;i++) {
if (elems == elt) {continue;} // don't test self
match=elems.name.match(gqCategoryRE);
if ( match && entry == +match[2] && // same entry
index == elems.selectedIndex) { // same selectedIndex
alert("Duplicate division selected! Please choose again.");
elt.selectedIndex = 0;
elt.focus(0);
return false;
}
}
return true;
}

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Duplicate values in drop down list box

marx

Lasse Reichstein Nielsen

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