advace validation with js

[deepM]

hello friends.

i am php programmer, i want to do js validation with my form.
in details like

!)i have product id, and that wanted to be an alphanumeric.
that is working perfectly fine with js.

2)but i want some formated alphanumeric value
e.g.
prod_id=L28
means first character should be alphabet and after i want only two digit

may be its too simple but i am new comer.
so please help me.
thanks in advance

[Pepejeria]

Easiest way to validate this is to use regular expressions. Get the value of the field and use the regular expression to validate.

[deepM]

could u please explain me with example means how i can do tht?

[deepM]

i ll tell you, what i am doing exactly,

if(document.productFrm.prod_id.value=="")
    {
        alert("Please enter your product id");
        document.productFrm.prod_id.focus();
        return false;
    } 

and i am chacking my alphanumeric value through php

}else if (!ctype_alnum($prod_id)){
    //  echo " This is alphanumeric <br/>";


              $prod_noErr      = "Please enter alphanumeric value";
              $validate           = 0; 

so please tell me, how to do this with js?

[Pepejeria]

Check out this thread.

You need to use the same concept. Your regular expressions to validate a word character followed by two numbers would look like this:

var re = /^\w\d{2}$/;

You can then check that the entered value matches your requirements in the following way:

var value = document.productFrm.prod_id.value;
var re = /^\w\d{2}$/;

if (re.test(value)) {
    alert("Value is valid");
    return true;
} else {
    alert("Entered value is not correct");
    return false;
}

[deepM]

thanks a lot pepejeria,

i will have look first on your links, and then ll try to understand how it works, and then let you know ok.

[Pepejeria]

PHP also provides good Regular Expression support. You might also want to validate the value on the server as well.

[deepM]

yes i am working on that also
see
what i have done here

function validate() {


           var value = document.productFrm.prod_id.value;
             var re =  /^\w\d{2}$/;
    
    if(document.productFrm.prod_id.value=="")
    {
        alert("Please enter your product id");
        document.productFrm.prod_id.focus();
        return false;
    }
    else if((document.productFrm.prod_id.value !="") && (isNaN(document.prod_id.value)==false))
    {
      if (re.test(value)) {
          alert("Value is valid");
          return true;
      } else {
          alert("Entered value is not correct");
          return false;
}
}
} 

but not working.

query-
1)re.test(value)- what is this? (is this function)

[Pepejeria]

Your code has several serious errors. Check out the Error Console in Firefox.

For example, missing } at the end and isNaN is misspelled. Also, why did you remove the backslashes from the regular expression?

[deepM]

ok, i have removed all errors
and pattern is
var re = /^\w\d{2}$/;

ok, but its not working. please tell what is going wrong here

[Pepejeria]

Your if else logic is a bit odd:

 
    if (document.productFrm.prod_id.value=="") {

    } else if(document.productFrm.prod_id.value !="")

There is no need to check if the string is not empty in the else since you already checked that in the if.

Anyway, I assume you read the other thread?

The ^ and the $ in the regular expression makes it unnecessary to check if the value empty is empty. Since it checks that the value starts with a word and ends with 2 numbers.