我知道这个问题已经被问过很多次了，但我找不到适合我的场景的答案。下面是我的代码。我在 findPattern 函数的最后一行中收到此错误。但我已在 createMyArea 中创建了 ID ，即 textArea += 'id="P'+app_page_id+'_VALUE'+key+'" 。但为什么找不到 ID ？请告诉我我在这里做错了什么。我在页面加载后加载它

var app_page_id         = 40;
var app_pattern_page_id     = 32;
var app_id;
var checksum;
var lang;

$(document).ready(function() {
    app_id = $("#pFlowId").val();
    checksum = $("#pInstance").val();

    createMyFlow();

    function createMyFlow(){
        var result = new htmldb_Get(null, $v('pFlowId'), 'APPLICATION_PROCESS='+getAllLanguagesProc,  $v('pFlowStepId'));
        lang = jQuery.parseJSON(result.get()).lang;
        createMyArea();
        result = loadDataFromMyOra();
        if(result !== null)
            findPattern(result);
    }

    function createMyArea(){
        var textArea;
        for ( var key in lang){
            textArea = '<tr><td  align="right"><label for="P'+app_page_id+'_VALUE_'+key+'">';
            textArea += '<span class="optional">Name '+languages[key][0]+': </span></label></td>';
            textArea += '<td  align="left" valign="middle">';
            textArea += '<input type="hidden" name="p_arg_names" />';
            textArea += '<fieldset id="P'+app_page_id+'_VALUE_fieldset_'+key+'" class="textarea" tabindex="-1">';
            textArea += '<input name="p_t04" type="text" maxlength="50" size="32" value=""';
            textArea += 'id="P'+app_page_id+'_VALUE'+key+'" required="" class="text_field"></fieldset>'
            textArea += '</td></tr>';
        $('.formlayout').append(textArea);
        }
    }

    function findPattern(patterns)
    {
        var item = "";
        for ( var key in patterns){
            item = patterns[key]+"";
            item = item.replace(/&#44;/g,",");
            item = item.replace(/&#8220;/g,'"')
            document.getElementById("P"+app_page_id+"_VALUE"+key).value = item;   //error here
        }
    }
});