// JavaScript Document
 function checkForm()
{
   var cfname, clname, cemail, cusername, cpasswd, cpasswd2, cuserid;
   with(window.document.register)
   {
      cfname    = fname;
      clname    = lname;
      cemail   = email;
      cusername = username;
      cpasswd = passwd;
      cpasswd2 = passwd2;
	  cuserid = user_id;
   }
   if(trim(cfname.value) == '')
   {
      alert('Please enter your first name');
      cfname.focus();
      return false;
   }
   else if(trim(clname.value) == '')
   {
      alert('Please enter your last name');
      clname.focus();
      return false;
   }
   else if(trim(cemail.value) == '')
   {
      alert('Please enter your email');
      cemail.focus();
      return false;
   }
   else if(!isEmail(trim(cemail.value)))
   {
      alert('Email address is not valid');
      cemail.focus();
      return false;
   }
   else if(trim(cusername.value) == '')
   {
      alert('Please enter a username');
      cusername.focus();
      return false;
   }
   else if(trim(cpasswd.value) == '' && cuserid == 0)
   {
      alert('Please enter a password');
      cpasswd.focus();
      return false;
   }
   else if(trim(cpasswd2.value) == '' && cuserid == 0)
   {
      alert('Please reenter your password');
      cpasswd2.focus();
      return false;
   }
   else if(trim(cpasswd.value) != trim(cpasswd2.value))
   {
      alert('Passwords different - please reenter');
      cpasswd.focus();
      return false;
   }
   else
   {
      cfname.value    = trim(cfname.value);
      clname.value    = trim(clname.value);
      cemail.value   = trim(cemail.value);
      cusername.value = trim(cusername.value);
      cpasswd.value = trim(cpasswd.value);
      cpasswd2.value = trim(cpasswd2.value);
      return true;
   }
}

function trim(str)
{
   return str.replace(/^\s+|\s+$/g,'');
}

function isEmail(str)
{
   var regex = /^[-_.a-z0-9]+@(([-_a-z0-9]+\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i;

return regex.test(str);
}