function trim(s) {

    if((s==null)||(typeof(s)!='string')||!s.length) {
        return '';
    }
    return s.replace(/^\s+/,'').replace(/\s+$/,'');

}

function check_blank(field) {

    if (field == '') {
        return false;
    }
    if (trim(field) == '') {
        return false;
    }
    return true;
}

function echeck(str) {

      var at="@";
      var dot=".";
      var lat=str.indexOf(at);
      var lstr=str.length;
      var ldot=str.indexOf(dot);

      if (str.indexOf(at)==-1){
	   return false;
      }

      if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
          return false;
      }

      if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
 	  return false;
      }

      if (str.indexOf(at,(lat+1))!=-1){
	  return false;
      }

      if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	  return false;
      }

      if (str.indexOf(dot,(lat+2))==-1){
          return false;
      }
		
      if (str.indexOf(" ")!=-1){
	  return false;
      }

      return true;					
}

function validate_contact() {
    
    var comments = document.form1.comments.value;
    var name = document.form1.name.value;
    var email = document.form1.email.value;
    var captcha = document.form1.captcha.value;

    if (!check_blank(name)) {
	alert('Name cannot be blank.');
	return false;
    }

    if (!check_blank(email)) {
	alert('Email cannot be blank.');
	return false;
    }

    if (!echeck(email)) {
	alert('Your email address is invalid.');
	return false;
    }

    if (!check_blank(comments)) {
	alert('Comments cannot be blank.');
	return false;
    }

    if (!check_blank(captcha)) {
	alert('You must input what you see in the image.');
	return false;
    }

    return true;
}