Динамическое управление позиционированием элементов
Поскольку у всех остальных элементов значение z-index не изменялось (и, следовательно, равно нулю), мы добиваемся того, что перемещаемый рисунок никогда не будет перекрыт другими объектами. Естественно, при окончании перемещения рисунка ему нужно возвратить исходное значение z-index. Для этого в функцию up_it() добавим строку:
document.all[moving].style.zlndex = 0;Итак, давайте посмотрим, что же у нас получается.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML>  <HEAD>    <TITLE>Игра 15</TITLE>    <STYLE>        BODY {             background-color: #979797;             color: #FEFEFE;             text-align: center;             font-weight: bold;             font-size: 30px;             font-family: sans-serif;         }     </STYLE>    <SCRIPT LANGUAGE="JavaScript" TYPE="text/javascript">        //<!--         var tstart;         var moving = "";           function mainpbs() {                 tstart = document.body.clientWidth / 2 - 200;                 document.a.is.rnaintab.style.left = tstart;                   function down_it() {                     var 1 == window.event.srcElement.src.length;                     if ((window.event.srcElement.tagName = "IMG") && (window.event.srcElement.src.substring(1 - 12, 1 - 4) != "diafanol")) {                         moving = window.event.srcElement.id;                         document.all[moving].style.pixelLeft = window.event.clientX - 50;                         document.all[moving].style.pixelTop = window.event.clientY - 50;                         document.all[moving].style.zlndex = 5;                     }                 }                   function up_it() {                     if (moving != "") {                         if (window.event.clientX >= tstart - 50 && window.event.clientY >= 50) {                             document.all[moving].style.pixelLeft = Math.round((window.event.clientX - 50 - tstart) / 100) * 100 + tstart + 1;                             document.all[moving].style, pixelTop = Math.round((window.event.clientY - 50) / 100) * 100 + 1;                         }                         document.all[moving].style.zlndex = 0;                         moving = "";                     }                 }                   function move_it() {                         if (moving != "") {                             document.all[moving].style.pixelLeft = window.event.clientX - 50;                             document.all[moving].style.pixelTop = window.event.clientY - 50;                         }                         event.cancelBubble = true;                         event.returnValue = false;                     }                     //-->     </SCRIPT></HEAD>  <BODY enLoad="mainpos()" onMouseDown="down_it()" onMouseUp="up_it()" onMouseMove="move_it()">    Расставьте плашки перетаскиванием с помощью мыши     <DIV ID="maintab" STYLE="width: 400px; height: 400px; position: absolute; top: 100px;">        TABLE BGCOLOR="#COCOCO" WIDTH="100%" CELLSPACING="0" CELLPADDING="0" BORDER="1">        <TR>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>        </TR>        <TR>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>        </TR>        <TR>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>        </TR>        <TR>            <TD>                <IMG SRC="Images/diafanol.gif" HIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>            <TD>                <IMG SRC="Images/diafanol.gif" WIDTH="98" HEIGHT="98">            </TD>        </TR>        </TABLE>    </DIV>    <IMG ID="p11" SRC="Images/digitll.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="11" STYLE="position: absolute; top: 60px; left: 50px;">    <IMG ID="p12" SRC="Images/digitl2.gif" WIDTH="100" HEIGHT="100" BORDER="0" AtlT="12" STYLE="position: absolute; top: 160px; left: 50px;">    <IMG ID="p13" SRC- "Images/digitl3.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="13" STYLE="position: absolute; top: 260px; left: 50px;">    <IMG ID="p14" SRC="Images/digitl4.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="14" STYLE="position: absolute; top: 360px; left: 50px;">    <IMG ID="p15" SRC="mages/digitl5.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="15" STYLE="position: absolute; top: 460px; left: 50px;">    <IMG ID="p6" SRC="Images/digit6.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="6" STYLE="position: absolute; top: 60px; left: 30px;">    <IMG ID="p7" SRC="Images/digit7.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="7" STYLE="position: absolute; top: 160px; left: 30px;">    <IMG ID="p8" SRC="Images/digit8.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="8" STYLE="position: absolute; top: 260px; left: 30px;">    <IMG ID="p9" SRC="Images/digit9.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="9" STYLE="position: absolute; top: 360px; left: 30px;">    <IMG ID="p10" SRC="Images/digitl0.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="10" STYLE="position: absolute; top: 460px; left: 30px;">    <IMG ID="p1" SRC="Images/digitl.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="1" STYLE="position: absolute; top: 60px; left: 10px;">    <IMG ID="p2" SRC="Images/digit2.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="2" STYLE="position: absolute; top: 160px; left: 10px;">    <IMG ID="p3" SRC="Images/digit3.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="3" STYLE="position: absolute; top: 260px; left: 10px;">    <IMG ID="p4" SRC="Images/digit4.gif" WIDTH="100" KEIGHT="100" BORDER="0" ALT="4" STYLE="position: absolute; top: 360px; left: 10px;">    <IMG ID="p5" SRC="Images/digit5.gif" WIDTH="100" HEIGHT="100" BORDER="0" ALT="5" STYLE="position: absolute; top: 460px; left: 10px;"></BODY>  </HTML>