向select中添加option，firefox和ie兼容

var result = Ext.util.JSON.decode(response.responseText); var domainsSelect = document.getElementById("domains"); var optionArray = new Array(); for (var i in result) { var option = document.createElement("option"); option.text = result[i]; option.value = i; optionArray[optionArray.length] = option; } optionArray = sortAsc(optionArray); for (var i = 0; i < optionArray.length; i++) { if (Ext.isIE) { domainsSelect.add(optionArray[i]); } else { domainsSelect.insertBefore(optionArray[i], domainsSelect.options[domainsSelect.length]); } }