JavaScript Fix Eval Return Error ?

<script language="javascript" type="text/javascript">
function testEval() {
	var code = "";

	// 在 eval 方法中,遇到 Return 時,會有 Error ?
	/*
	 * code = "if (10 === 10) { alert('Yes'); return true; } else { alert('No'); return false; }";
	 * eval(code);
	 */
	 

	// 解決方法?
	code += "new function() {";
	code += "	if (10 === 10) {";
	code += "		this.result = true;";
	code += "	}else{";
	code += "		this.result = false;";
	code += "	}";
	code += "	return this.result;";
	code += "}";

	alert(eval(code).result ? 'Yes' : 'No');
}

testEval();
</script>