Dropdownlist with javascript

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Hi,
In my web application i have a dropdownlist which get populated by some values from
database. I want if some one have not select any value from dropdownlist and click submit button the it must show alert messege like "you must select value from dropdownlist"
I tired to add conditionblock when user doesnot select values from dropdownlist in button click eventHandler as flows:

XML

System.Text.StringBuilder sbMessage = new StringBuilder();
                sbMessage.Append("<script type=\"text/javascript\">");
                sbMessage.Append("function alertMessage() {");
                sbMessage.Append("alert(\"please select value from dropdownlist\");");
                sbMessage.Append("}");
                sbMessage.Append("</script>");
                this.Page.RegisterClientScriptBlock("alerMessege", sbMessage.ToString());

but this doesnt show alert message can any one help me out here.

Posted 31-Mar-11 20:44pm

spydeehunk

Updated 31-Mar-11 21:51pm

Wild-Programmer

v2

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Wild-Programmer · Answer 1 · 2011-03-31T21:52:00

Solution 1

I think it should be

JavaScript

this.Page.RegisterClientScriptBlock(this.GetType(), "alertMessage", sbMessage.ToString());

There is spelling mistake in your code (alerMessege).

Posted 31-Mar-11 21:52pm

Wild-Programmer

Updated 31-Mar-11 22:05pm

v3

Comments

Raj.rcr 1-Apr-11 3:57am

But, still it doesn't work...

Wild-Programmer 1-Apr-11 4:04am

Use it like this

ClientScript.RegisterClientScriptBlock( typeof(Page), "myrest", "<script>alert('Hello');</script>");

Raj.rcr 1-Apr-11 4:19am

The good one Amit. Hope OP will get help from ur answer.. my 5

Wild-Programmer 1-Apr-11 4:44am

Thanx Raj

pankajupadhyay29 · Answer 2 · 2011-03-31T22:26:00

Solution 2

call onButtonClick function on submit button client click--

<script>
function onButtonClick()
{
dropdown=document.getElementById("<%=ddlSelect.ClientID %>")
if(dropdown.selectedIndex<0)
{
alert("Your msg");
return false;
}
return true;

}
</script>

--Pankaj

Posted 31-Mar-11 22:26pm

pankajupadhyay29