help on field validation...

[reigalz]

hi all....how do i validate a field whereby the users can only enter characters and numbers only?? which means they can't enter invalid characters like !@#$%^&*()..
thanks in advance ;)

[pankaj]

In Front Page if u select the text box and double click on it , u will see a window which has a validate button. select the appropriate options. This will generate a JScript function.
I suggest u go thru the function and change it according to ur needs.

[Mhtml]

Front page.. eeewwww.

<script>
function validate(theForm,theField){
string = theForm.theField;
var searchFor = "[^A-Za-z0-9_]";
s= string.search(searchFor);
return s;
}
</script>

[reigalz]

hi Mhtml, wat will s return? when will it return true?
can u explain abit on the code? thanks alot!

[Mhtml]

No problem, s will return a value greater than -1 if a bad character (!@#$%^&* etc..) is found, if it is all clean of the bad characters it will return -1..

You can change it like this to give an alert!

<script>
function validate(theForm,theField){
string = theForm.theField;
var searchFor = "[^A-Za-z0-9_]";
s= string.search(searchFor);
if (s == -1){
theForm.submit
}else{
alert("You have entered invalid characters!\n Please avoid using !@#$%^&*\(\) characters!";
}
}
</script>

[reigalz]

i tried, but there's an error....it says: Object doesn't support this property or method. Why is it so?

my form name is login and my field name is username so my code should be:

string = login.name;
var searchFor = "[^A-Za-z0-9_]";
s= string.search(searchFor);
if (s == -1){
login.submit
}else{
alert("You have entered invalid characters!\n Please avoid using !@#$%^&*\(\) characters!";
}

is it correct?

[Mhtml]

string = login.username.value;
var searchFor = "[^A-Za-z0-9_]";
s= string.search(searchFor);
if (s == -1){
login.submit()
}else{
alert("You have entered invalid characters!\n Please avoid using !@#$%^&*\(\) characters!");
}

[reigalz]

there's still the same error...
here's my code:

if(username.length>0 && a==0) {

string = login.username.value;
var searchFor = "[^A-Za-z0-9_]";
s = login.username.search(searchFor);

if(s==-1) {
return true;
} else {
window.alert("You have entered invalid characters!\n Please avoid using !@#$%^&*\(\) characters!");
a=1;
return false;
}

i'm using onSubmit..

[reigalz]

the error is at this line: s = login.username.search(searchFor);
do i need to define s?

[Mhtml]

s = login.username.value
s.search(searchFor)

[reigalz]

it works already! thanks for ur help! :D

[Mhtml]

No problem. :D

[Weirdan]

You'd better use character classes for validation:

var searchFor = "[\w]"

At present time it just equivalent to [A-Za-z0-9_] but someday ECMA will introduce locale-dependent regexp matching and Microsoft will implement it, I hope :)

[reigalz]

string = login.username.value;
var searchFor = "[^A-Za-z0-9_]";
s= string.search(searchFor);

the above code search for invalid characters...it also includes space....is there any code which only search for invalid characters except space....anyone noes? thanks in advance!