how to take either String or numbers..in txtbox

[madhuriks]

hi,
in my project...in one of the textbox...i need to take either numbersnumbers or NULL..im not getting any idea..can anyone help me out..here is my jsp code and js code..

login.jsp

 <td><font color="#800000" size=""><b>L-Acct. No.</b></font></td>
                        <td><input type="text" name="localAccNo" value=NULL></td>

login.js

if (document.frm.localAccNo.value == "")
    {
        alert("Enter Local A/c No. or 'NULL' in capitals");
        document.frm.localAccNo.focus();
        return (false);
    }
    var chkLocalAccNo = "0123456789";
    var chkLocalAccNoStr = document.frm.localAccNo.value;
    var allchkLocalAccNoValid = true;
    for (i = 0;  i < chkLocalAccNoStr.length;  i++)
    {
        ch = chkLocalAccNoStr.charAt(i);
        for (j = 0;  j < chkLocalAccNo.length;  j++)
            if (ch == chkLocalAccNo.charAt(j))
                break;
        if (j == chkLocalAccNo.length)
        {
            allchkLocalAccNoValid = false;
            break;
        }
    }
    if (!allchkLocalAccNoValid)
    {
        alert("Enter only numeric in the \" Local A/c No. \" field");
        document.frm.localAccNo.focus();
        return (false);
    }

thanks,
madhu.

[Dormilich]

I don’t understand your checking logic. you can test, whether an input qualifies for a number with either isFinite() or isNaN() (parseInt() would be a good starting point either, even RegExp were possible) and how to test for "NULL" I hopefully don’t have to explain.

[madhuriks]

hi,
i checked with the values..if i had given 'NULL' it is taking and if i give 'NULL123' is also taking...but i need is it should take either numbers or NULL that means

L-Acct. No.----> NULL
or
L-Acct. No.----> 123

like this i need i used RegExp..eventho ugh im not getting can u suggest me how to do..

[Dormilich]

how familiar are you with RegExp?

[madhuriks]

i m not that much familiar..im a learner

i used like this

if (document.frm.localAccNo.value == "")
    {
        alert("Enter Local A/c No. or 'NULL' in capitals");
        document.frm.localAccNo.focus();
        return (false);
    }
    var chkLocalAccNo = "[NULL/0123456] ";
    var chkLocalAccNoStr = document.frm.localAccNo.value;
    var allchkLocalAccNoValid = true;
    for (i = 0;  i < chkLocalAccNoStr.length;  i++)
    {
        ch = chkLocalAccNoStr.charAt(i);
        for (j = 0;  j < chkLocalAccNo.length;  j++)
            if (ch == chkLocalAccNo.charAt(j))
                break;
        if (j == chkLocalAccNo.length)
        {
            allchkLocalAccNoValid = false;
            break;
        }
    }
    if (!allchkLocalAccNoValid)
    {
        alert("Enter only numeric in the \" Local A/c No. \" field");
        document.frm.localAccNo.focus();
        return (false);
    }

[Dormilich]

no wonder that NULL123 worked …

ok, part one: how would you (in the simplest way) test for the string "NULL"?

[madhuriks]

if(document.frm.localAccNo.value == null){
alert(' null');
}else if(document.frm.localAccNo.value == 'null'){
alert('value is a string null');
}

[Dormilich]

looks good, but
- line 1/2 would also fire for "" (empty string).
- line 3/4 would not fire for "NULL" (or any version with capital letters)

tip: save the field’s value in a variable, that’s saving you (and the script) a massive amount of time.

[madhuriks]

i hope isNan() function should be used for this

[Dormilich]

isNan() would throw an error (because the function is called isNaN()), but it depends for what you need isNaN(). (as I already mentioned, isNaN() is one way to test a part of your requirements)

[madhuriks]

i didnt got ur point...can u help me how?

[Dormilich]

what will you use isNaN() for? there are codes, where isNaN() would definitely help, and codes where it were absolutely pointless.

[madhuriks]

hi,
gud mrng..i tried..its getting but the problem is if i enter 'NULL123' it is not showing error..can u suggest me where to change the code..here is my code..

login.js

 var chkLocalAccNo = document.frm.localAccNo.value;
    //check if it is not a number
    var validation = true;
    for (var i = 0; i < chkLocalAccNo.length; i++ )
    {
        if (isNaN(chkLocalAccNo.charAt(i)))
        {
            //if it is not a number check if it is NULL
            if (chkLocalAccNo == 'NULL')
            {
                validation = true;
                document.frm.localAccNo.focus();
            }
            else
            {
                validation = false;
                document.frm.localAccNo.focus();
            }
        }
    }

thanx and waiting for the reply.
madhu.

[Dormilich]

discard the loop.

[madhuriks]

i discard for loop eventhough it is not getting..