dhtmlxValidation.trackInput is not a function

I write this code but don’t work. Why?

Grid code


Validator code

dhtmlxValidation.maxlength8 = function(data)
return maxlength(data,8);

dhtmlxValidation.maxlength1 = function(data)
return maxlength(data,1);

maxlength = function(value,length)
return (value.length() <= length);

I receive from firebug two different notification:

Please check if you have included dhtmlxgrid_validation.js file to your page

Thank you!