if (typeof window.cs=="undefined")
    window.cs = {};
    
if (typeof window.cs.string=="undefined")
    window.cs.string = {};
    
cs.string.isEmptyString = function(str){
    if (str==undefined)
        return true;
    else if (str.length==0)
        return true;
    else
        return false;
};

cs.string.isPatternMatch = function(str, rePattern){
    if (str == undefined)
        return false;
    else
    {
        if (typeof rePattern == "string")
        {
            switch (rePattern)
            {
                case "email":
                    rePattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
                    break;
            }
        }
        
        return rePattern.test(str);
    }
};