Validating a drop down (select) type, form element

[Terry Murray]

Hi everybody:


I am trying to write a generic function, isValidMonth, that can used on 2
form elements, smonth and emonth. I would like the function to test whether
the user has selected a month or not.
If anyone can help me I would really appreciate it. What I have done
follows.

My form has:

<SELECT name=smonth>
<OPTION value=0>-Month-
<OPTION value=1>Jan
<OPTION value=2>Feb
<OPTION value=3>Mar
...
<OPTION value=12>Dec
</SELECT>

<SELECT name=emonth>
<OPTION value=0>-Month-
<OPTION value=1>Jan
<OPTION value=2>Feb
<OPTION value=3>Mar
...
<OPTION value=12>Dec
</SELECT>
..
My JavaScript contains:

function isValidMonth(mo nth) {
if (month[month.selectedI ndex].value == 0
return false
return true
}


function submitIt(form) {
if (!isValidmonth( smonth))
alert("You have not selected a start month")
return true
}

Thank you

Terry

[kaeli]

Re: Validating a drop down (select) type, form element

In article <Q6jLb.34347$AJ B.14159@news04. bloor.is.net.ca ble.rogers.com> ,
tgmurray@rogers .com enlightened us with...[color=blue]
>
> <SELECT name=smonth>[/color]

quote attributes.
sname="month"
[color=blue]
> <OPTION value=0>-Month-[/color]
value="0"
[color=blue]
> .
> My JavaScript contains:
>
> function isValidMonth(mo nth) {
> if (month[month.selectedI ndex].value == 0
> return false
> return true
> }
>[/color]

Better programming practice (only one exit) and a correction

function isValidMonth(mo nth) {
b = true;
if (month.options[month.selectedI ndex].value == 0
b = false
return b
}
[color=blue]
>
> function submitIt(form) {
> if (!isValidmonth( smonth))
> alert("You have not selected a start month")
> return true
> }
>[/color]

return value needed; keyword changed; correction to call

function submitIt(frm) {
b = true;
if (isValidmonth(f rm.smonth))
{
alert("You have not selected a start month");
b = false;
}
return b
}

handler called in onSubmit of form, not onClick of submit

<form name="f1" action="whateve r" method="post" onSubmit="retur n
submitIt(this)" >

--
--
~kaeli~
A little rudeness and disrespect can elevate a meaningless
interaction to a battle of wills and add drama to an
otherwise dull day.

http://www.ipwebdesign.net/wildAtHeart

http://www.ipwebdesign.net/kaelisSpace

[Lasse Reichstein Nielsen]

Re: Validating a drop down (select) type, form element

kaeli <tiny_one@NOSPA M.comcast.net> writes:
[color=blue]
> Better programming practice (only one exit) and a correction[/color]

I'm not sure I agree with that practice in all cases.
[color=blue]
> function isValidMonth(mo nth) {
> b = true;
> if (month.options[month.selectedI ndex].value == 0[/color]

Missing ")". I recommend { ... } around all if branches, even if they
are only a single statement. It makes it easier to extend them later.

From the original poster's description, I would just test:
month.selectedI ndex == 0
since his invalid option was the first one.
[color=blue]
> b = false
> return b
> }[/color]

.... but when it comes to returning booleans with if-statements,
I always want to do it shorter:

function isValidMonth(mo nth) {
return month.selectedI ndex != 0;
}

Otherwise, I agree.
/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'

[Terry Murray]

Re: Validating a drop down (select) type, form element

Thanks Kaeli. I think a correction is needed for the code that you provided
me with.
if (!isValidmonth( frm.smonth)) should replace if
(isValidmonth(f rm.smonth)) inside of function submitIt(frm).

Terry



"kaeli" <tiny_one@NOSPA M.comcast.net> wrote in message
news:MPG.1a6784 3e98fd5a32989a9 a@nntp.lucent.c om...[color=blue]
> In article <Q6jLb.34347$AJ B.14159@news04. bloor.is.net.ca ble.rogers.com> ,
> tgmurray@rogers .com enlightened us with...[color=green]
> >
> > <SELECT name=smonth>[/color]
>
> quote attributes.
> sname="month"
>[color=green]
> > <OPTION value=0>-Month-[/color]
> value="0"
>[color=green]
> > .
> > My JavaScript contains:
> >
> > function isValidMonth(mo nth) {
> > if (month[month.selectedI ndex].value == 0
> > return false
> > return true
> > }
> >[/color]
>
> Better programming practice (only one exit) and a correction
>
> function isValidMonth(mo nth) {
> b = true;
> if (month.options[month.selectedI ndex].value == 0
> b = false
> return b
> }
>[color=green]
> >
> > function submitIt(form) {
> > if (!isValidmonth( smonth))
> > alert("You have not selected a start month")
> > return true
> > }
> >[/color]
>
> return value needed; keyword changed; correction to call
>
> function submitIt(frm) {
> b = true;
> if (isValidmonth(f rm.smonth))
> {
> alert("You have not selected a start month");
> b = false;
> }
> return b
> }
>
> handler called in onSubmit of form, not onClick of submit
>
> <form name="f1" action="whateve r" method="post" onSubmit="retur n
> submitIt(this)" >
>
> --
> --
> ~kaeli~
> A little rudeness and disrespect can elevate a meaningless
> interaction to a battle of wills and add drama to an
> otherwise dull day.
> http://www.ipwebdesign.net/wildAtHeart
> http://www.ipwebdesign.net/kaelisSpace
>[/color]