name validation using javascript regular expressions

Below is the javascript code along with implementation to validate the names for allowing alphabet characters only using regular expressions.

This code also supports spacing between the words in the names.


function validateNames(name)
{ 
var letters = /^[A-Za-z\s]+$/;
if(name.match(letters))
{
return true;
}
else
{
return false;
}
}


//Usage
var empname=trim(document.getElementById("employeename").value);

if(validateNames(empname))
    {
        //return true;
    }
    else if((empname=="") || (empname=="0") || (empname=="null")  || (empname=="NIL") || (empname=="nil"))
    {
        alert('Please enter valid Employee Name');
           return false;
    }
    else
    {
        alert('Employee name must have alphabet characters only');
           return false;
    }



//trim function
function trim(s) {
          
             while (s.substring(0,1) == ' ') {
                s = s.substring(1,s.length);
              }
              while (s.substring(s.length-1,s.length) == ' ') {
                s = s.substring(0,s.length-1);
              }
              return s;
            
            }