input框中内容正常情况下被禁止修改

%26lt;!-- 把下面代码加到%26lt;body%26gt;区域中 --%26gt;
%26lt;form method="post" action="" name="form3"%26gt;
%26lt;input type="checkbox" name="add_add" value="Y" onclick="check_add()"%26gt;
%26lt;select name="catalog_select"%26gt;%26lt;option value=32%26gt;选择分类%26lt;/option%26gt;%26lt;option value="2"%26gt;大话时事%26lt;option value="33"%26gt;整人专家%26lt;option value="34"%26gt;性致盎然%26lt;option value="35"%26gt;信短情长%26lt;option value="36"%26gt;友情信使%26lt;option value="37"%26gt;温馨家庭%26lt;/select%26gt;
%26lt;script%26gt;
function check_add()
{
if (document.form3.add_add.checked)
{
document.form3.catalog_select.disabled=false;
}
else
{
document.form3.catalog_select.disabled=true;
}
}
check_add();
%26lt;/script%26gt;
%26lt;BR%26gt;%26lt;input type="checkbox" name="checkboxtime" value="checkbox" onclick="add_time()"%26gt;
定时%26lt;select name="select2"%26gt;
%26lt;option%26gt;2001%26lt;/option%26gt;
%26lt;option%26gt;2002%26lt;/option%26gt;
%26lt;/select%26gt;
年
%26lt;select name="select3"%26gt;
%26lt;option selected%26gt;1%26lt;/option%26gt;
%26lt;option%26gt;2%26lt;/option%26gt;
%26lt;option%26gt;3%26lt;/option%26gt;
%26lt;option%26gt;4%26lt;/option%26gt;
%26lt;option%26gt;5%26lt;/option%26gt;
%26lt;option%26gt;6%26lt;/option%26gt;
%26lt;option%26gt;7%26lt;/option%26gt;
%26lt;option%26gt;8%26lt;/option%26gt;
%26lt;option%26gt;9%26lt;/option%26gt;
%26lt;option%26gt;10%26lt;/option%26gt;
%26lt;option%26gt;11%26lt;/option%26gt;
%26lt;option%26gt;12%26lt;/option%26gt;
%26lt;/select%26gt;
月
%26lt;select name="select4"%26gt;
%26lt;option%26gt;1%26lt;/option%26gt;
%26lt;option%26gt;2%26lt;/option%26gt;
%26lt;option%26gt;3%26lt;/option%26gt;
%26lt;option%26gt;4%26lt;/option%26gt;
%26lt;option%26gt;5%26lt;/option%26gt;
%26lt;option%26gt;6%26lt;/option%26gt;
%26lt;option%26gt;7%26lt;/option%26gt;
%26lt;option%26gt;8%26lt;/option%26gt;
%26lt;option%26gt;9%26lt;/option%26gt;
%26lt;option%26gt;10%26lt;/option%26gt;
%26lt;option%26gt;11%26lt;/option%26gt;
%26lt;option%26gt;12%26lt;/option%26gt;
%26lt;option%26gt;13%26lt;/option%26gt;
%26lt;option%26gt;14%26lt;/option%26gt;
%26lt;option%26gt;15%26lt;/option%26gt;
%26lt;option%26gt;16%26lt;/option%26gt;
%26lt;option%26gt;17%26lt;/option%26gt;
%26lt;option%26gt;18%26lt;/option%26gt;
%26lt;option%26gt;19%26lt;/option%26gt;
%26lt;option%26gt;20%26lt;/option%26gt;
%26lt;option%26gt;21%26lt;/option%26gt;
%26lt;option%26gt;22%26lt;/option%26gt;
%26lt;option%26gt;23%26lt;/option%26gt;
%26lt;option%26gt;24%26lt;/option%26gt;
%26lt;option%26gt;25%26lt;/option%26gt;
%26lt;option%26gt;26%26lt;/option%26gt;
%26lt;option%26gt;27%26lt;/option%26gt;
%26lt;option%26gt;28%26lt;/option%26gt;
%26lt;option%26gt;29%26lt;/option%26gt;
%26lt;option%26gt;30%26lt;/option%26gt;
%26lt;option%26gt;30%26lt;/option%26gt;
%26lt;option%26gt;31%26lt;/option%26gt;
%26lt;/select%26gt;
日
%26lt;select name="select5"%26gt;
%26lt;option%26gt;0%26lt;/option%26gt;
%26lt;option%26gt;1%26lt;/option%26gt;
%26lt;option%26gt;2%26lt;/option%26gt;
%26lt;option%26gt;3%26lt;/option%26gt;
%26lt;option%26gt;4%26lt;/option%26gt;
%26lt;option%26gt;5%26lt;/option%26gt;
%26lt;option%26gt;6%26lt;/option%26gt;
%26lt;option%26gt;7%26lt;/option%26gt;
%26lt;option%26gt;8%26lt;/option%26gt;
%26lt;option%26gt;9%26lt;/option%26gt;
%26lt;option%26gt;10%26lt;/option%26gt;
%26lt;option%26gt;11%26lt;/option%26gt;
%26lt;option%26gt;12%26lt;/option%26gt;
%26lt;option%26gt;13%26lt;/option%26gt;
%26lt;option%26gt;14%26lt;/option%26gt;
%26lt;option%26gt;15%26lt;/option%26gt;
%26lt;option%26gt;16%26lt;/option%26gt;
%26lt;option%26gt;17%26lt;/option%26gt;
%26lt;option%26gt;18%26lt;/option%26gt;
%26lt;option%26gt;19%26lt;/option%26gt;
%26lt;option%26gt;20%26lt;/option%26gt;
%26lt;option%26gt;21%26lt;/option%26gt;
%26lt;option%26gt;22%26lt;/option%26gt;
%26lt;option%26gt;23%26lt;/option%26gt;
%26lt;/select%26gt;
时
%26lt;script%26gt;
function add_time()
{
if (document.form3.checkboxtime.checked)
{
document.form3.select2.disabled=false;
document.form3.select3.disabled=false;
document.form3.select4.disabled=false;
document.form3.select5.disabled=false;
}
else
{
document.form3.select2.disabled=true;
document.form3.select3.disabled=true;
document.form3.select4.disabled=true;
document.form3.select5.disabled=true;
}
}
add_time();
%26lt;/script%26gt;%26lt;/form%26gt;