username verification

ravi951 · #1 (**permalink**) July 19th, 2011, 05:48 AM

Hi all,
I have written a function for accepting name and should be atleast minimum 4 characters.
It is accepting all characters including special characters.
Now i want my function to accept only a-z0-9 and _(underscore),-(hyphen)
and .(dot)
Below is my function

function checkName(form) /* for real name verification */
{
if (form.realname.value == '')
{
alert('Error: Username cannot be blank!');
form.realname.focus();
return false;
}
else if(form.realname.value.length < 4)
{
alert("UserName should be atleast 4 characters long");
return false;
}

return true;
}

joefawcett · #2 (**permalink**) July 19th, 2011, 06:22 AM

I think you need a regular expression:

Code:

function testUsername(text)
{
  var oRE = /^[\w\d-.]{4,}$/g;
  var isCorrectFormat = oRE.test(text);
  //alert(isCorrectFormat);
  return isCorrectFormat;
}

I haven't tested the above.

ravi951 · #3 (**permalink**) July 19th, 2011, 06:28 AM

k,can u give me with out using regular expression so that the
above written should fit with it.

joefawcett · #4 (**permalink**) July 19th, 2011, 06:36 AM

You can just add my bit after your current code.

Code:

function checkName(form) /* for real name verification */
{
if (form.realname.value == '') 
{
alert('Error: Username cannot be blank!');
form.realname.focus(); 
return false;
}
else if(form.realname.value.length < 4)
{
alert("UserName should be atleast 4 characters long"); 
return false;
}
  var oRE = /^[\w\d-.]{4,}$/g;
  var isCorrectFormat = oRE.test(text);
  if (!isCorrectFormat)
  {
    alert("Invalid characters in username. It can only contain...");
    return false;
  }
return true;
}

ravi951 · #5 (**permalink**) July 19th, 2011, 06:41 AM

are you sure that it will accept characters a-z and numbers 0-9
and three special characters .(dot),-(hypen) and_(underscore).

joefawcett · #6 (**permalink**) July 19th, 2011, 06:48 AM

Well you're allowed to test it yourself.

ravi951 · #7 (**permalink**) July 19th, 2011, 07:12 AM

hi dude the function is not working
it is accepting other functions such as !,@,# and so on other than .,_,-
below is the code i have written..

function checkName(form) /* for real name verification */
{
var oRE =/^[\w\d-.]{4,}$/g;
var isCorrectFormat = oRE.test(form);
if (!isCorrectFormat)
{
alert("Invalid characters in username. It can only contain 0-91-9._-");
return false;
}

else if (form.realname.value == '')
{
alert('Error: Username cannot be blank!');
form.realname.focus();
return false;
}
else if(form.realname.value.length < 4)
{
alert("UserName should be atleast 4 characters long");
return false;
}

return true;
}

joefawcett · #8 (**permalink**) July 19th, 2011, 07:21 AM

You're testing against the form, not the value in the textbox.

ravi951 · #9 (**permalink**) July 19th, 2011, 07:27 AM

then what to do to work for value in the text box

joefawcett · #10 (**permalink**) July 19th, 2011, 07:48 AM

Code:

function checkName(form) /* for real name verification */
{
  var sRealName = form.realname.value;

else if (sRealName  == '') 
{
alert('Error: Username cannot be blank!');
form.realname.focus(); 
return false;
}
else if(sRealName.length < 4)
{
alert("UserName should be atleast 4 characters long"); 
return false;
}
var oRE =/^[\w\d-.]{4,}$/g;
var isCorrectFormat = oRE.test(sRealName);
if (!isCorrectFormat)
{
alert("Invalid characters in username. It can only contain 0-91-9._-");
return false;
} 

return true;
}

Need to download code?

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