Convert Text Field to Picklist

The Code uses a simpe trick which takes the text field id , assigns it to a new picklist field and deletes it from the form, when the crmForm is saved the picklist is recognized as a valid attribute and its data is sent to the server "for safe keeping...".

function CrmPageOnLoad() {   
   ConvertTextToPickList( "[ControlId]"); 
}

function ConvertTextToPickList( controlId ) {
  //Referance the Text field
  var textControl = document.getElementById( controlId );
  //Create a new Picklist (SELECT) control
  var picklistControl = document.createElement( "SELECT" );
  //Copy the Text field properties to the picklist
  picklistControl.id = textControl.id;
  picklistControl.req = textControl.req;
  //Set Required Style
  picklistControl.className = "ms-crm-SelectBox "; //"selectBox " v3.0
  AddPickListValues( picklistControl );
  //load the picklist selected value from the text field (saved) datavalue
  picklistControl.value = textControl.DataValue;
  //append the picklist to the document
  textControl.parentElement.appendChild( picklistControl );
  //remove the text field , we don't need it anymore.
  textControl.parentElement.removeChild( textControl );
  //Done 
}

function AddPickListValues( picklistControl ) {
  var picklistValues = GetPickListValues();
  for( var i = 0 ; i < picklistValues.length; i++ )
  {
    //Create a new Option
    var option = document.createElement( "OPTION" );
    //In this case the value and text are the same
    option.value = option.innerText = picklistValues[i];
    //Add the option to the picklist
    picklistControl.appendChild( option );
  } 
}

function GetPickListValue() {
  //This is just a stub , you can load the values from the server as well
  return [ 'A' , 'B' , 'C' ]; 
}

CrmPageOnLoad();