JSFiddle - React, Tailwind, and code Playground
HTML
<table id="ContentPlaceHolder1_AccountsTable" style="width:100%;margin-top:20px; text-align:center;">
<tr>
<td><span class="AccountSelectBox"><input id="chk7701997" type="checkbox" name="ctl00$ContentPlaceHolder1$chk7701997" /><label for="chk7701997">7701997</label></span></td><td>7701997</td><td>05/07/2014</td><td></td><td><input name="ctl00$ContentPlaceHolder1$txt7701997" type="text" id="txt7701997" disabled="disabled" class="aspNetDisabled AccountAmountBox" style="width:50px;" /></td>
</tr><tr>
<td><span class="AccountSelectBox"><input id="chk28183452" type="checkbox" name="ctl00$ContentPlaceHolder1$chk28183452" /><label for="chk28183452">28183452</label></span></td><td>28183452</td><td>05/07/2014</td><td></td><td><input name="ctl00$ContentPlaceHolder1$txt28183452" type="text" id="txt28183452" disabled="disabled" class="aspNetDisabled AccountAmountBox" style="width:50px;" /></td>
</tr>
</table>
JavaScript
$(".AccountSelectBox input:checkbox").change(function () {
if(this.checked)
$(this).closest("tr").find('.AccountAmountBox').removeAttr("disabled");
else
$(this).closest("tr").find('.AccountAmountBox').prop("disabled",true);
});
$('.AccountAmountBox').blur(function(){
alert($(this).val())
})