The first is the js code that limits the number of checkboxes: Copy the code The code is as follows: "http://www.w3.org/TR/html4/loose.dtd"> < html> Restrict checkbox selection Quantity <br>function checkDate(n){ <br> var checkedCount=0; <br> for(var i=0;i< myForm.course.length ;i ++){ <BR> if(myForm.course[i].checked){ <BR> checkedCount++; <br><br> } <BR> } <BR> if(checkedCount>n ){ <br><br> alert("Cannot choose more than three courses"); <br><br> return false; <br><br> } <br> } <br><br></script> ; <BR></head> <br><body> <br><form name="myForm" method="post" id="myForm" action="test.php"> <br>Please Select courses for this semester (up to three courses): <br> <br><input type="checkbox" name="course[]" value="Chinese" onClick="return checkDate(3)">Chinese <br> <br><input type="checkbox" name="course[]" value="Mathematics" onClick="return checkDate(3)">Mathematics<br> <br><input type ="checkbox" name="course[]" value="English" onClick="return checkDate(3)">English<br> <br><input type="checkbox" name="course[]" value="Chemistry" onClick="return checkDate(3)">Chemistry<br> <br><input type="checkbox" name="course[]" value="Physics" onClick="return checkDate( 3)">Physics<br> <br><input type="checkbox" name="course[]" value="Politics" onClick="return checkDate(3)">Politics<br> <br><input type="submit" value="Submit"> <br><input type="reset" value="Cancel"> <br></form> <br></body> ; <BR></html> <br> </div> <br><strong>Then the method of getting checkbbox from php file: <br></strong><div class="codetitle"> <span style="CURSOR: pointer" onclick="doCopy('code29804')"><u>Copy code</u> </span> The code is as follows:</div> <div class="codebody" id="code29804"> <br><?php<BR>$course=$_POST['course'];<BR>for($i=0;$i<count($course );$i++) <BR>{ <BR>if($course[$i]!="") <BR>{<BR>echo $course[$i]."<br/>";<br>} <br>} <br>?><br> </div> <br> <p align="left"></p> <div style="display:none;"> <span id="url" itemprop="url">http://www.bkjia.com/PHPjc/328112.html</span><span id="indexUrl" itemprop="indexUrl">www.bkjia.com</span><span id="isOriginal" itemprop="isOriginal">true</span><span id="isBasedOnUrl" itemprop="isBasedOnUrl">http: //www.bkjia.com/PHPjc/328112.html</span><span id="genre" itemprop="genre">TechArticle</span><span id="description" itemprop="description">The first is the js code that limits the number of checkbboxes: Copy the code as follows: !DOCTYPE HTML PUBLIC "-/ /W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd" h...</span> </div> <div class="art_confoot"></div>
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