代码如下：
<script> function checkBoxValidate(cb) { for (j = 0; j < 8; j++) { if (eval("document.myform.ckbox[" + j + "].checked") == true) { document.myform.ckbox[j].checked = false; if (j == cb) { document.myform.ckbox[j].checked = true; } } } } </script> <form name=myform> <div align="center">选框 1 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(0)"> <br> 选框 2 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(1)"> <br> 选框 3 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(2)"> <br> 选框 4 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(3)"> <br> 选框 5 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(4)"> <br> 选框 6 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(5)"> <br> 选框 7 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(6)"> <br> 选框 8 <input type="checkbox" name="ckbox" onClick="javascript:checkBoxValidate(7)"> <br> </div> </form>