diff --git a/lib/client/dom.js b/lib/client/dom.js
index 5628b503..e8339cf9 100644
--- a/lib/client/dom.js
+++ b/lib/client/dom.js
@@ -1264,7 +1264,7 @@ var CloudCmd, Util, DOM, CloudFunc, Dialog;
                 
                 parallel([loadHash, getStoreHash], function(error, loadHash, storeHash) {
                     var equal,
-                        isContain   = Util.isContainStr(loadHash, 'error');
+                        isContain   = /error/.test(loadHash);
                     
                     if (isContain)
                         error = loadHash;
diff --git a/lib/client/load.js b/lib/client/load.js
index ac197358..02cce63b 100644
--- a/lib/client/load.js
+++ b/lib/client/load.js
@@ -194,7 +194,7 @@ var Util, DOM;
             });
             
             Events.add('readystatechange', xhr, function(event) {
-                var TYPE_JSON, type, data, isContain,
+                var TYPE_JSON, type, data, isContain, notText,
                     xhr         = event.target;
                 
                 if (xhr.readyState === 4 /* Complete */) {
@@ -204,14 +204,13 @@ var Util, DOM;
                     
                     if (xhr.status === 200 /* OK */) {
                         data        = xhr.response;
-                        isContain   = Util.isContainStr(type, TYPE_JSON);
+                        notText     = p.dataType !== 'text',
+                        isContain   = ~type.indexOf(TYPE_JSON);
                         
-                        if (p.dataType !== 'text')
-                            /* If it's json - parse it as json */
-                            if (type && isContain)
-                                data = Util.json.parse(xhr.response) || xhr.response;
+                        if (type && isContain && notText)
+                            data = Util.json.parse(xhr.response) || xhr.response;
                             
-                            Util.exec(p.success, data, xhr.statusText, xhr);
+                        Util.exec(p.success, data, xhr.statusText, xhr);
                     }
                     /* file not found or connection lost */
                     else {
diff --git a/lib/client/storage/_github.js b/lib/client/storage/_github.js
index 1d2624de..afc9e385 100644
--- a/lib/client/storage/_github.js
+++ b/lib/client/storage/_github.js
@@ -62,7 +62,7 @@ var CloudCmd, Util, join, DOM, CloudFunc, Github, cb;
                     if (!code)
                         code = window.location.search;
                     
-                    isContain = Util.isContainStr(code, '?code=');
+                    isContain = ~code.indexOf('?code=');
                     
                     if (!isContain)
                         DOM.openWindow(URL);
diff --git a/lib/server/ponse.js b/lib/server/ponse.js
index d31b960a..2bb08cfd 100644
--- a/lib/server/ponse.js
+++ b/lib/server/ponse.js
@@ -106,12 +106,11 @@
             type            = ext[extension] || 'text/plain',
             encoding        = '';
             
-            /* if type of file any, but img - then we shoud specify charset */
-            isContain       = Util.isContainStr(type, ['img', 'image', 'audio']);
+            isContain       = /img|image|audio/.test(type);
             if (!isContain)
                 encoding    = '; charset=UTF-8';
             
-            isContain        = Util.isContainStr(p.query, 'download');
+            isContain        = /download/.test(p.query);
             if (isContain)
                 type        = 'application/octet-stream';
             
diff --git a/lib/util.js b/lib/util.js
index bbd7557b..77463026 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -235,40 +235,6 @@
             return ret;
         };
         
-        /**
-         * function returns is str1 contains str2
-         * @param str1
-         * @param str2
-         */
-         
-        this.isContainStr           = function(str1, str2) {
-            var i, n, str, is, index,
-                isStr   = Util.type.string(str1),
-                type    = Util.type(str2);
-            
-            if (isStr)
-                switch (type) {
-                case 'array':
-                    n  = str2.length;
-                     
-                    for (i = 0; i < n; i++) {
-                        str = str2[i];
-                        is  = Util.isContainStr(str1, str);
-                        
-                        if (is)
-                            break;
-                    }
-                    break;
-                
-                case 'string':
-                    index   = str1.indexOf(str2);
-                    is      = index >= 0;
-                    break;
-                }
-            
-            return is;
-        };
-        
         /**
          * function log pArg if it's not empty
          * @param pArg