1，js限制checkbbox勾选个数的代码：
<!DOCTYPE HTML <span public> "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>限制复选框选择的数量-www.jbxue.com-脚本学堂</title> <script type="text/javascript" > <span function> <span checkdate><span><span var> checkedCount=0<span><span for>(<span var> i=0;i<myForm.course.length ;i ++<span><span if>(myForm.course[i].<span checked checkedcount>++<span><span if>(checkedCount><span n alert>"不能选超过三门课程"<span><span return> <span false><span></script> </head> <body> <form name="myForm" method="post" id="myForm" action="test.php"><span><br> <input type="checkbox" name="course[]" value="语文" onClick="return checkDate(3)">语文<br> <input type="checkbox" name="course[]" value="数学" onClick="return checkDate(3)">数学<br> <input type="checkbox" name="course[]" value="英语" onClick="return checkDate(3)">英语<br> <input type="checkbox" name="course[]" value="化学" onClick="return checkDate(3)">化学<br> <input type="checkbox" name="course[]" value="物理" onClick="return checkDate(3)">物理<br> <input type="checkbox" name="course[]" value="政治" onClick="return checkDate(3)">政治<br> <input type="submit" value="提交"> <input type="reset" value="取消"> </form> </body> </html></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
<?<span php><span><span edit by www.jbxue.com><span> <span>=<span>['course'<span><span for>(<span>=0;<span><<span count>(<span>);<span>++<span><span if>(<span>[<span>]!=""<span><span echo> <span>[<span>]."<br/>"<span>?></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
