function validateEmailAFriend(st_mail, r_mail, mail_msg, sizeChars, msg_field_name) {
    if (validate_st_mail(st_mail, 'Please enter "To" email address.', 'Please fill in a valid "To" email address.') && validate_r_mail(r_mail) && validate_mail_msg(mail_msg, sizeChars, msg_field_name)) {
		return true;
    }
	return false;	
}

function validate_st_mail(st_mail) {
	return validate_st_mail(st_mail, "", "");
}

function validate_st_mail(st_mail, error_msg1, error_msg2) {
    //To remove space
    while(st_mail.indexOf(" ")!=-1){
        st_mail = st_mail.substring(0,st_mail.indexOf(" "))+  st_mail.substring(st_mail.indexOf(" ")+1,st_mail.length);
    }

    if(checkEmptyStr(st_mail)){
		if (error_msg1) {
			alert (error_msg1);
		} else {
			alert ('Please enter email address.');
		}
		return false;
    }
    st_mail = lrTrim(st_mail);

	var origString = st_mail;  
	var newString = origString.split(";");  
	newString = newString.join(",");
	st_mail = newString;

    var strArr = st_mail.split(",");

    if(strArr.length>5){
        alert('Maximum 5 email addresses are allowed.');
		return false;
    }

    for(var i=0;i<strArr.length;i++){
    	var emailStr = lrTrim(strArr[i]);
		if (validateEmail(emailStr) != "") {
			if (error_msg2) {
				alert (error_msg2);
			} else {
				alert('Please fill in a valid email address.' );
			}
			return false;
		}
    }

    return true;
}

function validate_r_mail(r_mail) {
	if(checkEmptyStr(r_mail) || r_mail.indexOf(",")!=-1){
		alert('Please enter "From" email address.');
		return false;
	}

	var r_mail = lrTrim(r_mail);

	if (validateEmail(r_mail) != "") {
		alert('Please fill in a valid "From" email address.' );
		return false;
	}

	return true;
}

function validate_mail_msg(mail_msg, sizeChars, msg_field_name) {
	if(!checkEmptyStr(mail_msg)){
		mail_msg = lrTrim(mail_msg);
		if(mail_msg.length >= sizeChars){
			alert("Maximum " + sizeChars + " characters are allowed in '" + msg_field_name + "' field.");
			return false;
		}
	} 
	return true;
}

function checkEmptyStr(str) {
	if(str==""){
		return true;
    }
	return false;
}