Block Styler Values to an Expression

Using BlockStyler I have created a Dialog Box that asks the user for 3 linear dims to define the size of a folded sheet metal part. I have set up a group of Expressions that will create the part based on these 3 dims. I am having problems exporting the values out of the blockstyler box and into the expressions. Any help or suggestions would be appreciated.

Thanks
Scott

public int update_cb( NXOpen.BlockStyler.UIBlock block)
{
try
{
if(block == integer0)
{
int xx = block.GetProperties().GetInteger("Value");
Part w = theSession.Parts.Work;

Expression xs = w.Expressions.CreateExpression("Integer", xx.ToString());

//---------Enter your code here-----------
}
}
catch (Exception ex)
{
//---- Enter your exception handling code here -----
theUI.NXMessageBox.Show("Block Styler", NXMessageBox.DialogType.Error, ex.ToString());
}
return 0;
}