代码示例展现PHP二级联动菜单的实现

对于初学者来说，

PHP二级联动菜单代码示例：

1. script language = "JavaScript">
2. var onecount;
3. onecount=0;
4. subcat = new Array();
5. ?php
6. mysql_connect("localhost","charles",
   "charles");
7. mysql_select_db( "_crm" );
8. $sql = "select * from site";
9. $result = mysql_query( $sql );
10. $count = 0;
11. while($res = mysql_fetch_row($result)){
12. ?>
13. subcat[ ?php echo $count ?>] = new Array
    (" ?php echo $res[0]?>"," ?php echo
    $res[2]?>"," ?php echo $res[1]?>");
14. ?php
15. $count++;
16. }
17. echo "onecount=$count;";
18. ?>
19. //联动函数
20. function changelocation(locationid)
21. {
22. document.myform.ctype.length = 0;
23. var locationidlocationid=locationid;
24. var i;
25. for (i=0;i onecount; i++)
26. {
27. if (subcat[i][2] == locationid)
28. {
29. //var newnewOption1=new Option(subcat[i]
    [1], subcat[i][0]);
30. //document.all.ctype.add(newOption1);
31. document.myform.ctype.options[document.
    myform.ctype.length] = new Option(subcat
    [i][1], subcat[i][0]);
32. }
33. }
34. }
35. /script>
36. form method="post" name="myform"
    action="ru_query.php">
37. select name="type" onChange="changelocation(
    document.myform.type.options[document.myfo
    rm.type.selectedIndex].value)" size="1">
38. option selected value="">main /option>
39. ?php
40. $sql = "select * from entreprise";
41. $result = mysql_query( $sql );
42. while($res = mysql_fetch_row($result)){
43. ?>
44. option value="">
45. ?php echo $res[1]; ?> /option>
46. ?php } ?>
47. /select>
48. select name="ctype">
49. option selected value="">sub /option>
50. /select>
51. input type="submit" name="Submit" value="search">
52. /form>

以上代码就是PHP二级联动菜单的具体实现方法。