function ShowTree($first = 0, $node_id = "", $index = 0) {
if($first == 0){
    echo"<select name=\"Category_id\" onchange=\"MM_jumpMenu('parent',this,0)\">";
    $first = 1;
}
    if (strlen(trim($node_id)) == 0) $condition = "Category_id is NULL";
    else $condition = "Category_id = {$node_id}";
    
    $prefix = "";
    for($i = 0; $i < $index; $i++) $prefix = $prefix."  ";
    
    $sqlstat = "SELECT id, Category FROM Category WHERE {$condition}";
    $result = mssql_query($sqlstat);
    while($row = mssql_fetch_array($result)) {
        $Element_id = $row["id"];
        $ElementValue = $row["Category"];
        
        $this_sql = "SELECT cnt = count(*) FROM Category WHERE Category_id = {$Element_id}";
        $this_res = mssql_query($this_sql);
        $this_cnt = mssql_result($this_res, 0, "cnt");
        
        $ans_sql = "SELECT cnt = count(*) FROM Answer WHERE Category_id = {$Element_id}";
        $ans_res = mssql_query($ans_sql);
        $ans_cnt = mssql_result($ans_res, 0, "cnt");
        
        if ($this_cnt > 0) {
            echo "<option value =".$row["id"]." >{$prefix}{$ElementValue}</option>";
            ShowTree($first, $Element_id, $index + 1);    
        } else {
            if ($ans_cnt > 0) {
                echo "<option value =".$row["id"]." >{$prefix}{$ElementValue}</option>";
            } else echo "<option value =".$row["id"]." >{$prefix} - {$ElementValue}</option>";
        }    
    }
    return $Category_id;
}