Scriptmanager警告框

Question

如何将条件添加到scriptmanager的onxlick on aspx.cs中。

ScriptManager.RegisterClientScriptBlock(
    this, 
    this.GetType(), 
    "alertMessage", 
    "alert('Would you like to be put on the wait list?')", 
    true);

 if(onclick == true)
    {
    //do something}
    }
    else 
    {
    //do something
    }