Auto tab at the end of a value if there is one in the field?

I wish to know if there is a way to set focus at the end of the value when there is already one entered in the field. I have taken the information in this forum on how to auto tab. I have this in the document JavaScript :

function goNext(item, event, cName)

{

AFNumber_Keystroke(0,0,0,0,"",true);

if(event.rc && AFMergeChange(event).length ==event.target.charLimit) item.getField(cName).setFocus();

}

And this on mousedown under the Action tab of the field property :

this.getField("ShortT.1").setFocus(); 

This focuses on the entire field and selects whatever is in it. Is there a possibility of just moving the cursor at the end?

Thank you.