Multiple-choice list box implemented by JavaScript

1. <Script language = "JavaScript">
2. Function mm_findobj (n, d) {// v4.0
3. VaR P, I, X; If (! D) d = document; if (P = n. indexof ("? ")> 0 & parent. frames. Length ){
4. D=parent.frames[n.substring(p%1%].doc ument; n = n. substring (0, P );}
5. If (! (X = d [N]) & D. All) x = D. All [N]; for (I = 0 ;! X & I <D. Forms. length; I ++) x = D. Forms [I] [N];
6. For (I = 0 ;! X & D. Layers & I <D. layers. length; I ++) xw.mm_findobj(n,d.layers+ I }.doc ument );
7. If (! X & document. getelementbyid) x = Document. getelementbyid (n); Return X;
8. }
9. Function checkposttype (DES, OP ){
10. If (! Des |! OP) return true;
11. VaR flag = true;
12. VaR Ops = des. options;
13. VaR I = 0;
14. For (I = 0; I <ops. length; I ++ ){
15. If (Ops. Item (I). value = op. Value ){
16. Flag = false;
17. }
18. If (Ops. Item (I). Value % 100 = 0 & ops. Item (I). value = op. value-op.value % 100 ){
19. Flag = false;
20. }
21. If (! Flag ){
22. Alert ('option ['+ ops. Item (I). innertext +'] already contains ['+ OP. innertext +']. ');
23. Return flag;
24. }
25. If (op. Value % 100 = 0 & OP. value = ops. Item (I). value-ops.item (I). Value % 100 ){
26. Ops. Remove (I );
27. I --;
28. }
29. }
30. Return flag;
31. }
32. // This function allows you to delete and move selected items from the list to another list. 2001/04/04
33. // Parameter table:
34. // SRC Source list
35. // List of des targets (if omitted, the items selected in the source list will be deleted)
36. // Exce if the text of an item in the source list is the same as this parameter, the item cannot be removed or deleted (can be omitted)
37. // D1 specifies the framework or window in which the source list is located (if omitted, search in the current framework or window)
38. // D2 specifies the frame or window in which the target list is located (if omitted, search in the current frame or window)
39. //
40. Function selmove (SRC, Des, check, exce, D1, D2, del) {If (! SRC) return false;
41. VaR osrc = mm_findobj (SRC, D1 );
42. If (! Osrc) return false;
43. If (! Des ){
44. For (I = 0; I <osrc. Options. length; I ++ ){
45. If (osrc. Options (I). Selected ){
46. If (osrc. Options (I). innertext! = Exce ){
47. Osrc. Options. Remove (I );
48. I --;
49. }
50. }
51. }
52. }
53. Else {
54. VaR odes = mm_findobj (DES, D2 );
55. If (! ODES) return false;
56. For (I = 0; I <osrc. Options. length; I ++ ){
57. VaR osrcoption = osrc. Options. item (I );
58. If (osrcoption. Selected ){
59. If (check & check (ODES, osrcoption )){
60. If (osrcoption. innertext! = Exce ){
61. VaR ooption = Document. createelement ("option ");
62. Odes. Options. Add (ooption );
63. Ooption. innertext = osrcoption. innertext;
64. Ooption. value = osrcoption. value;
65. Osrcoption. Selected = false;
66. If (DEL) {osrc. Options. Remove (I); I --;}
67. }
68. }
69. }
70. }
71. }
72. }
74. Function check_city (DES, OP ){
75. If (checkposttype (DES, OP )){
76. If (DES. Options. length> = 3 ){
77. Alert ("no more than three! ");
78. Return false;
79. }
80. Else return true;
81. }
82. Else {
83. Return false;
84. }
85. }
86. Function selselectedall (osrc ){
87. If (! Osrc) return false;
88. VaR I;
89. For (I = 0; I <osrc. Options. length; I ++ ){
90. Osrc. Options. Item (I). Selected = true;
91. }
93. }
94. Function check ()
95. {
96. Selselectedall (document. form1. B)
97. }
98. </SCRIPT>
99. <Form ID = "form1" name = "form1" method = "Post" Action = "B. asp">
100. <Select name = "A" size = "10" multiple = "multiple" id = "A" style = "width: 180px; font-size: 12px;">
101. <Option value = "1"> 1 </option>
102. <Option value = "2"> 2 </option>
103. <Option value = "3"> 3 </option>
104. <Option value = "4"> 4 </option>
105. <Option value = "5"> 5 </option>
106. </SELECT>
107. <A href = "#" onclick = "selmove ('A', 'B', check_city)"> Add </a>
108. <Select name = "B" size = "10" multiple = "multiple" id = "B" style = "width: 180px; font-size: 12px;">
110. </SELECT>
111. <Input type = "Submit" name = "button" id = "button" value = "Submit" onclick = "check ()"/>
112. </Form>