1. 如果您不改变表单的行为，为什么使用JavaScript来提交表单？，您已经在提交按钮中。
   

2. 您应该尝试给出表单名称=mosForm，而不仅仅是id =mosForm，以便可以找到该事件处理程序的DOM引用。

I have a code (see it below). It works perfectly in Firefox: it saves submitted information after clicking __JL_SAVE button and keeps user on same page. But in Internet Explorer & Opera it only redirects to index page (index.php) and doesn't save submitted information. What can I do for solving this problem? Thanks.

Here is my code:

<form action="index.php" id="mosForm" method="post" enctype="multipart/form-data">

    <fieldset>
        <legend><?=__JL_ABOUT_MYSELF?></legend>
        <span class="a" onclick="showHideLegend('about_myself_1')"><?=__JL_EDIT_BLOCK;?></span>
        <div id="about_myself_descr" style="display: block"><?=__JL_SELF_DESCR;?></div>
        <div id="about_myself_1" style="display: none"><?php include "html/about_myself_fill.php"?></div>
        <div id="about_myself_2""><?php include "html/about_myself_show.php"?></div>
    </fieldset>

    <fieldset>
        <legend><?=__JL_ABOUT_MYSELF?></legend>
        <span class="a" onclick="showHideLegend('type_1')"><?=__JL_EDIT_BLOCK;?></span>
        <?php if ($typ_block) {?>
            <?php /* <input type="checkbox" id="jl_type_block" name="jl_type_block" <?php if ($roon_type_block) echo 'checked ';?> /> */ ?>
            <input type="checkbox" id="jl_type_block" name="jl_type_block" disabled <?php  echo 'checked ';?> />
            <label for="jl_type_block"><?=__JL_ON_BLOCK?></label>
        <?php } else {
            echo __JL_OFF_BLOCK;
        }?>

        <div id="about_myself_descr" style="display: block"><?=__JL_SELF_DESCR;?></div>

        <div id="type_1" style="display : none">
            <?php include "html/type.php"?>
        </div>
        <?php if ($typ_block) { ?>
            <div id="type_2">
                <?php include "html/type_show.php"?>
            </div>
        <?php } ?>
        </fieldset>

        <fieldset>
            <legend><?=__JL_INTEREST?></legend>
            <span class="a" onclick="showHideLegend('interest_1')"><?=__JL_EDIT_BLOCK;?></span>
            <?php if ($interest_block) {?>
                <input type="checkbox" id="jl_interest_block" name="jl_interest_block" disabled <?php echo 'checked ';?> />
                <label for="jl_interest_block"><?=__JL_ON_BLOCK?></label>
            <?php } else
                echo __JL_OFF_BLOCK;
            ?>
            <div id="interest_descr" style="display:block"><?=__JL_INTEREST_DESCR;?></div>
            <div id="interest_1" style="display:none">
                <?php include "html/interest.php"?>
            </div>
            <?php if ($interest_block) { ?>
                <div id="interest_2">
                <?php include "html/interest_show.php"?>
                </div>
            <?php } ?>
        </fieldset>


            <input type="submit" name="save" value="__JL_SAVE" onClick="mosForm.submit();" />
            <input type="hidden" name="option" value="com_joomlove" />
            <input type="hidden" id="task" name="task" value="save_info" />
            </form>

Full source available here: http://narkoz.pastebin.com/f4f036f5

1. If you're not changing the behavior of the form, why use JavaScript to submit the form?, you're already in a submit button.

2. You should try giving the form name="mosForm", not just id="mosForm", so that the DOM reference from that event handler can be found.