function validate(lang) {
	var validRegExp, s_remail, s_rname, s_semail, s_sname, error1, error2, error3, error4, errorgen, errorthank, errormsg
	
	validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
	
	s_remail=document.forms[0].f_remail.value;
	s_rname=document.forms[0].f_rname.value;
	s_semail=document.forms[0].f_semail.value;
	s_sname=document.forms[0].f_sname.value;
	
	if (lang == 'english') {
		error1 = 'recipient email address is invalid or empty';
		error2 = 'recipient name must not be empty';
		error3 = 'your email address is invalid or empty';
		error4 = 'your name must not be empty';
		errorgen = 'Please check if the following fields are entered correctly:';
		errorthank = 'Thank you.';
	}

	errormsg = '';

	if (s_remail == '' || s_remail.search(validRegExp) == -1) {
	errormsg += '\n- '+error1;
	}
	if (s_rname == '') {
	errormsg += '\n- '+error2;
	}
	if (s_semail == '' || s_semail.search(validRegExp) == -1) {
	errormsg += '\n- '+error3;
	}
	if (s_sname == '') {
	errormsg += '\n- '+error4;
	}
	
	if (errormsg !='') {
		alert(errorgen+'\n'+errormsg+'\n\n'+errorthank);
		document.forms[0].btnSubmit.value = 'Submit';
		document.forms[0].btnSubmit.disabled = false;
		return false;	
	}
	
	return true;
}