Username should take alphabets

[meeanji]

Hi friends, i need to write validation for textbox(Usernme ) which should accept only alphabets. I am able throw validation that Please fill the UserName Details.Now it should throw that it accepts only alphabets.My code goes like this::

<tr>
	   <td style="width:30%" align="right">User Name :</td>
	   <td style="width:70%"> <input name="username" size="20" maxlength="155" value="<?php echo $username;?>"   onfocus="setVisibility('100','inline')"; onBlur="setVisibility('100','none')"> </td>
	 </tr>
<tr>
	   <td align="right">Password :</td>
	   <td> <input name="password" type="password" size="20" maxlength="155" value="<?php echo $password;?>"   onfocus="setVisibility('100','inline')"; onBlur="setVisibility('100','none')"> </td>
	     
	   </tr>


<script type="text/javascript">


function validate_form ( )
{
    valid = true;
    
    if ( document.msgform.username.value == "" )
    {
        alert ( "Please fill the UserName Details." );
        valid = false;
    }
    else if(document.msgform.password.value == "")
	{
	 alert ( "Please fill the Password Details." );
        valid = false;
	}
return valid;
	
}	
	
<td>
	 <td>  <input type="submit" name="submit" value="Submit"  onClick="return validate_form();"></td></div>
	   </td>
 

</script>

Please can anybody tellme how to write validations for this username that it should accept only Alphabets.

Regards,
meeanji

[acoder]

You could use a regular expression, e.g. /^[a-z]+$/i You can use the match method of the string to test if it matches the regular expression, e.g.
[code=javascript]var username = document.msgfor m.username.valu e;
if (!username.matc h(/^[a-z]+$/i) {
// you can alert here...
[/code]