Asp.net回车提交

txtpwd.Attributes.Add("onkeydown", "if(event.which || event.keyCode){   if ((event.which == 13) || (event.keyCode == 13)) {   document.getElementById('" + LinkButton1.UniqueID + "').click();return false;}}    else {return true}; ");
txtuid.Attributes.Add("onkeydown", "if(event.which || event.keyCode){   if ((event.which == 13) || (event.keyCode == 13)) {   document.getElementById('" + LinkButton1.UniqueID + "').click();return false;}}    else {return true}; ");