在一個表單中有很多CheckBox，請問如何實現選種一個而讓所有的都選中？???
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function??selectAll(checkBoxName){???
???????????var??elms??=??document.getElementsByName(checkBoxName);???
???????????if??(elms.length<1)??return;???
???????????var??allChecked??=??true;???
???????????for??(var??i=0;i<elms.length;i++)???
???????????????????????if??(elms[i].type=="checkbox")???
???????????????????????????????????allChecked??&=??elms[i].checked;???
???????????for??(var??i=0;i<elms.length;i++)???
???????????????????????if??(elms[i].type=="checkbox"){???
???????????????????????????????????????????????elms[i].checked??=??!allChecked;???
???????????????????????????????????????????????if??(elms[i].onclick)??elms[i].onclick();???
???????????????????????}???
}???
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<input??type=checkbox??name=m><input??type=checkbox??name=m><input??type=checkbox??name=m><input??type=checkbox??name=m>???
<input??type=checkbox??name=m><input??type=checkbox??name=m><input??type=checkbox??name=m><input??type=checkbox??name=m>?????
?全選<input??type=checkbox??value="Check??All"??onclick="mm(this)">?????

<script??language=javascript>???????
function??mm(o)???
{???
?????var??a??=??document.getElementsByName("m");???
?????for??(var??i=0;??i<a.length;??i++){???
?????????a[i].checked??=??o.checked;???
?????}???

}???
</script>?


<input?type=checkbox?name=chk>?
<input?type=checkbox?name=chk>?
<input?type=checkbox?name=chk>?
<input?type=checkbox?name=chk>?
<input?type=checkbox?name=chk>?
<br>?
全選：<input?type=checkbox?onclick=sel('chk')>?
<script?language="javascript">?
?function?sel(a){??
??o=document.getElementsByName(a)??
??for(i=0;i<o.length;i++)??
??o[i].checked=event.srcElement.checked??
?}?
</script>??