My Llink button is not firing(Source code attached)

Question

Llink button is not firing, but working when commented the code in page load

In one of my page MeasurementNew.aspx and cs page having this issue.

Link button is not working. If I commented the code in page load including !postback,its firing but the dropdown named dddemandnumber failed to load.

2.Add new item is another button in the grid which is having same function in the above link button also not working

protected void btnNewItem_Click(object sender, EventArgs e)

gridview:gvdetail

Enable tracing and check the axd file in new tab.checked link button time, attributes, lost timings etc. Also delete the link buttons entire link. Then rebuild and drag and drop the link

its working when no selection in dropdown.when i select a value in dropdown the page displayed according to that value..But link button still dead

protected void lbtnSRBook_Click(object sender, EventArgs e) { Response.Write("123"); } works on link button click.but when i add the code instead of " Response.Write("123")" not working