<script> var checkobj function agreesubmit(el){ checkobj=el if (document.all||document.getElementById){ for (i=0;i<checkobj.form.length;i++){ //hunt down submit button var tempobj=checkobj.form.elements[i] if(tempobj.type.toLowerCase()=="submit") tempobj.disabled=!checkobj.checked } } } function defaultagree(el){ if (!document.all&&!document.getElementById){ if (window.checkobj&&checkobj.checked) return true else{ alert("Please read/accept terms to submit form") return false } } } </script> <form name="agreeform" onSubmit="return defaultagree(this)"> <input name="agreecheck" type="checkbox" onClick="agreesubmit(this)"><b>你确认这些都是正确的了吗？</b><br> <input type="Submit" value="提交" disabled> </form> <script> //change two names below to your form's names document.forms.agreeform.agreecheck.checked=false </script>