How to call postback using javascript on ASP.NET form

Question

I have a web form with textbox and button. I want after "ENTER" key click on textbox postbak form.

I am using next code:

onkeypress=" if(event.keyCode==13)
 { alert(2);
WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions('ctl00$ContentPlaceHolder1$btnSearch', '', true, '', '', false, false));
alert(2); 
return false;}

where WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions('ctl00$ContentPlaceHolder1$btnSearch', '', true, '', '', false, false));

is javascript code for button event onclick.

I get two alerts, but postback doesnot happen.

Any ideas what is wrong?

Solution

ASP.NET already creates a client side javascript method __doPostBack to support postback.

Example: __doPostBack('__Page', 'MyCustomArgument');