voici pour info le code
aspx
<body>
<form id="form1" runat="server">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<input type="button" value="Clear" onclick="hello();" />
<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
</form>
</body>
cs
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
TextBox1.Text = "UIUIUI";
}
}
protected void Button1_Click(object sender, EventArgs e)
{
//TextBox1.Text vaudra ""
}