Run a function on button click

I want run a Script on a button click (because you cannot run a function in your script ona button click) I've followed the Suitescript documentation and am only able to get the first like (a log line) to run. Any idea?
` form.setScript('customscript_toloader') form.addButton('custpagetestbutton', 'TEST button', 'createTO();');`
-Other script
function createTO() //(request, response)
{   
alert("This function was called");
//variable set up
      nlapiLogExecution('DEBUG', 'script', 'runs 1');
    var POID ;
    var POType ;
    var PORecord;
    var lines;
  nlapiLogExecution('DEBUG', 'script', 'runs 2');
    var arrayName = new Array();
    var arrayQty = new Array();
    PORecord = nlapiGetNewRecord();
    lines = PORecord.getLineItemCount('item');
    POID = nlapiGetRecordId();