Form validation problem

JavaScript
1

I am using a function (below) for validation. However, if the first condition is true then all the conditions after do not execute, e.g. the form doesnt alert any error messages…any ideas? (code is below)

// chkNumeric is an external function, see at the end.

function validate_form ( )
{
valid = true;

if( ( document.xform.name.value == "" ) || ( document.xform.terms.value == "" )|| ( document.xform.terms.value=="" )
|| (document.xform.buiness_name.value=="")|| ( document.xform.location.value =="" )|| ( document.xform.min_qty.value=="" )
|| ( document.xform.max_qty.value == "") || ( document.xform.description.value == "" ) )
{
	$.prompt ('Please complete all required fields (* is required)');
    valid = false;
}
	if(chkNumeric(document.xform.min_qty.value)==false)
{
	$.prompt('Minimum quantity must be a number!');
	valid=false;
}
	if(chkNumeric(document.xform.max_qty.value)==false)
{
	$.prompt('Maximum quantity must be a number!');
	valid=false;
}

return valid;

}

function chkNumeric(strString)
// strString is the string passed to be checked

// check for valid numeric strings
{
// strvalidchars defines the set of characters which are valid in a numeric field
var strValidChars = “0123456789.-”;
// strings
var strChar;
// boolresult is the variable which returns true is string is in correct format or false if it is not a valid numeric string
var boolResult = true;

 if (strString.length == 0) return false;

// test strString consists of valid characters listed above
for (i = 0; i < strString.length && boolResult == true; i++)
{
strChar = strString.charAt(i);
if (strValidChars.indexOf(strChar) == -1)
{
boolResult = false;
}
}
return boolResult;
}

2

The only reason I can see here for Javascript to stop executing would be a syntax error, but this code has no errors.

Have you checked if $.prompt is working correctly?

3

yes $.prompt works fine, as it is executing if I submit the form and the first “if” is false, the other if’s also get executed at the same time, but if the first “if” is true, the others dont get executed independantly

4

just added the other function that i was calling inside the main function

5

One mistake in your chkNumeric function:

for (i = 0; i < strString.length && boolResult == true; i++)

i = 0, you have to declare i first in javascript, so change this line to:

for (var i = 0; i < strString.length && boolResult == true; i++)

6

Since variable declarations are automatically hoisted to the top of the existing scope, it’s preferred to declare all variables at the start of the function that they’re in, so as to reduce any confusion.


var i;

for (i = 0; i < strString.length && boolResult == true; i++) {
7

Also, one of the useful benefits of placing variable declarations at the start is that it’s easier to see if lots of unrelated variables are being used. If that’s the case then it’s a good early warning that you should split things up in to a couple of separate functions.

8

By the way, all of the code for chkNumeric can be replaced with a regular expression test.


function chkNumeric(strString) {
    return !isNaN(Number(strString));
}

Where isNaN() and [url=“https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Number”]Number() are built-in methods that already do the job for you.