This javascript cut & paste code snippet will only let the viewer enter their name into the form if they indicate they agree to the terms by first clicking the "I Agree radio button". If viewer agrees they may enter their name. If they disagree they will not be able to enter, or edit their name. When viewer disagrees the input box is locked. Useful if you require your visitors to accept a disclaimer before downloading software, or visiting a members-only section.

Insert this code into your HEAD of HTML

<!-- // == This Script Free To Use Providing This Notice Remains == // // == This Script Has Been Found In The http://www.DesignerWiz.com Javascript Public Archive Library == // // == NOTICE: Though This Material May Have Been In A Public Depository, Certain Author Copyright Restrictions May Apply == // --><script language="JavaScript" type="text/javascript"> <!-- Begin agree = 0; // 0 means 'no', 1 means 'yes' // End --> </script>

Insert this code into your BODY section

<center> <form name=enableform> You can only enter your name if you agree to the terms. (just a demo)<br> <br> <input type=radio name='enable' value='agree' onClick="agree=1; document.enableform.box.focus();">I agree<br> <input type=radio name='enable' value='disagree' onClick="agree=0; document.enableform.box.value='';">I disagree<br> Please enter your name: <input type=text name=box onFocus="if (!agree)this.blur();" onChange="if (!agree)this.value='';" size=12> <br> <br> <input type="submit" value="Done!" class="hexfield1"> </form></center>

Simply Cut and Paste Script code
Be sure to properly place script position in HEAD & BODY sections of html 

This script has been in the DesignerWiz.com Public Library.