Add javascript and fire it from DataGrid control

				
//**************************************
// Name: Add javascript and fire it from DataGrid control
// Description:Allows the firing of a javascript from within a control embedded in a datagrid.
// By: James Fleming
//
// Assumes:This javascript tests the length of a multiline textbox & fires off an error message if it is too long.
Assumes you know how to build & populate a datagrid:
this example contains 2 columns (provided)
 <asp:TemplateColumn HeaderText="Next Step" ItemStyle-Width="2%">
 <ItemTemplate>
<asp:TextBox id="txtNEXT_STEP" Width=120 maxlength=50 runat="server" Rows=2 Wrap=True Text='<%# Container.DataItem("NEXT_STEP").tostring()%>' Height="40" TextMode="MultiLine">
</asp:TextBox>
<asp:RequiredFieldValidator ID="valNext_Step" ControlToValidate="txtNEXT_STEP" Display="None" ErrorMessage="The Next Step is a required field."></asp:RequiredFieldValidator>
 </ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="Comments" ItemStyle-Width="2%">
 <ItemTemplate>
<asp:TextBox id="txtComments" Width=200 maxlength=40 runat="server" Text='<%# Container.DataItem("COMMENTS").tostring()%>' Rows="2" Height="40">
</asp:TextBox>
<asp:RequiredFieldValidator ID="valComments" ControlToValidate="txtComments" Display="None" ErrorMessage="The Comments is a required field."></asp:RequiredFieldValidator>
 </ItemTemplate>
</asp:TemplateColumn>
//
//This code is copyrighted and has// limited warranties.Please see http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=1108&lngWId=10//for details.//**************************************

First the javascript:
Dim sb As New System.Text.StringBuilder()
sb.Append("<SCRIPT LANGUAGE = javascript>")
sb.Append("<!-- " & vbCrLf)
sb.Append(" function charCount(txt, chars, control){" & vbCrLf)
sb.Append("var txtLen=txt.value;" & vbCrLf)
sb.Append("var len = chars - txtLen.length; " & vbCrLf)
sb.Append("if (txtLen.length > chars){" & vbCrLf)
sb.Append("alert('The length of the ' + control + ' may only be ' + chars + ' long. \n The length must be shorter by ' + -len + ' characters.');" & vbCrLf)
sb.Append("}" & vbCrLf)
sb.Append("}" & vbCrLf)
sb.Append("--></script>" & vbCrLf)
RegisterClientScriptBlock("cs", sb.ToString)
Next:
In the code behind during the loading of the grid or during the edit event you add the Attributes to the textboxs in the grid:
For i = 0 To grdData.Items.Count - 1
 CType(grdData.Items(i).FindControl("txtNEXT_STEP"), TextBox).Attributes.Add("onBlur", "charCount(" & CType(grdData.Items(i).FindControl("txtNEXT_STEP"), TextBox).ClientID & ",50, 'Next Step')")
 CType(grdData.Items(i).FindControl("txtComments"), TextBox).Attributes.Add("onBlur", "charCount(" & CType(grdData.Items(i).FindControl("txtComments"), TextBox).ClientID & ",255, 'Comments')")
Next