Java Script For dropdown list

Arul R

Hi Friends ...

When i write javascript for droplist and text box validation.

The below error came.I don't know which type of error.

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Please do needful

4 Replies

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Arul R14y ago
In the text box contain AJAX calender ctrl...so may be the error came
Jaish Mathews14y ago
Can you check 2 things

1. 1st whether this JS method you pasted is getting executed? put a break point in JS and try
2. Remove the JS method call from HTML side and see whether the error you mentioned here appearing or not?
Arul R14y ago
Hi This is my code .. if (document.getElementById("<%=txtcomp.ClientID%>").value == "") { alert("Name Feild can not be blank"); document.getElementById("<%=txtcomp.ClientID%>").focus(); return false; }
Jaish Mathews14y ago
In 1st look, it's seeing that your JS call is under a block, some thing like "<% ... %>". This block will always parse as a server side code, but JS is client side. That seems to be the problem. So you please check your HTML part and make sure that JS calls are out of the block "<% ... %>".