function validate_form() {
	if (document.thisform.sb_name.value == "") {
		alert ("Please enter your name.");
		document.thisform.sb_name.focus();
		return false;
	}
	
	if (document.thisform.sb_email.value == "") {
		alert ("Please enter your email address.");
		document.thisform.sb_email.focus();
		return false;
	}

	function isEmail(str) {
	  var supported = 0;
	  if (window.RegExp) {
	    var tempStr = "a";
	    var tempReg = new RegExp(tempStr);
	    if (tempReg.test(tempStr)) supported = 1;
	  }
	  if (!supported) 
	    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
	  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
	  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
	  return (!r1.test(str) && r2.test(str));
	}
	if (isEmail(document.thisform.sb_email.value) == false) {
		alert ("Please enter a valid email address.");
		document.thisform.sb_email.focus();
		return false;
	}
	
	if (document.thisform.sb_address.value == "") {
		alert ("Please enter your address.");
		document.thisform.sb_address.focus();
		return false;
	}
	if (document.thisform.sb_city.value == "") {
		alert ("Please enter your city.");
		document.thisform.sb_city.focus();
		return false;
	}
	if (document.thisform.sb_state.value == 0) {
		alert ("Please enter your state.");
		document.thisform.sb_state.focus();
		return false;
	}
	
	return true;
}