title: validation in jqgrid
body: <p>im currently working on jqgrid using ci framework. just want to ask about the validation in jqgrid. I've seen that in jqgrid a column can be validated like this: editrules: {required:true}}, and so on...</p>
  
  <p>heres my question, i want to know if its possible that if a client enters his/her desired username but it already exist. Is this possible using the jqgrid validations? </p>
  
  <p>thanks
  -Dean</p>