function checkFormCheckVvailability(form)
{

    msg="Please fill out these fields or correct errors:";
    errorFlag=false;
    isSetFocus=false;

    if (form.name.value=="")
    {
        errorFlag = true;
        msg=msg+"\n Name is empty";
        if(!isSetFocus)
        {
            form.name.focus();
            isSetFocus= true;
        }
    }

    var reg = new RegExp("^[a-z0-9_\\.\\-]+@+[a-z0-9_\\.\\-]+(\\.[a-z]{2,4})$","gi");
    if (form.email.value=="")
    {
        errorFlag=true;
        msg=msg+"\n Email is empty";
        if(!isSetFocus)
        {
            form.email.focus();
            isSetFocus = true;
        }
    }else{
        if (!reg.test(form.email.value))
        {
            errorFlag=true;
            msg=msg+"\n Email is not valide";
            if(!isSetFocus)
            {
                form.email.focus();
                isSetFocus = true;
            }
        }
    }

    if (form.num_adults.value=="")
    {
        errorFlag=true;
        msg=msg+"\n Number of adults is empty";
        if(!isSetFocus)
        {
            form.num_adults.focus();
            isSetFocus = true;
        }
    }

    if (form.num_children.value=="")
    {
        errorFlag=true;
        msg=msg+"\n Number of childrens is empty";
        if(!isSetFocus)
        {
            form.num_children.focus();
            isSetFocus = true;
        }
    }

    if (form.arrival_date.value=="")
    {
        errorFlag=true;
        msg=msg+"\n Arrival date is empty";
        if(!isSetFocus)
        {
            form.arrival_date.focus();
            isSetFocus = true;
        }
    }

    if (form.comments.value=="")
    {
        errorFlag=true;
        msg=msg+"\n Question/comment field is empty";
        if(!isSetFocus)
        {
            form.comments.focus();
            isSetFocus = true;
        }
    }

    if (!errorFlag)
    {
        return true;
    }else{
        alert(msg);
        return false;
    }
}